# How Humans Became Humans: The Evolution of You and Me

An episode of [TheThinkingAtheist](https://invisiblenetwork.ai/podcast/412308695), 4 Feb 2025, 1 h 52 min.

Audio: https://dts.podtrac.com/redirect.mp3/mgln.ai/e/711/api.spreaker.com/download/episode/64084190/podcast786_howhumansbecamehumans.mp3

Biological anthropologist "Gutsick Gibbon" walks us through 7 million years...and the evolution of human beings. VIDEO: https://youtu.be/PUZ9p4Ao4K4?si=YnZ7VLjulhys63I2 GUTSICK GIBBON: https://www.youtube.com/@GutsickGibbon Become a supporter of this podcast: https://www.spreaker.com/podcast/thethinkingatheist--3270347/support.

## Transcript

[0:05] Speaker 1: The Thinking Atheist. It's not a person, it's a symbol,
[0:09] Speaker 1: an idea.
[0:10] Speaker 2: The population of atheists in this country is going through the.
[0:13] Speaker 1: Rule, rejecting faith, pursuing knowledge, challenging the sacred. If I
[0:19] Speaker 1: tell the truth, it's because I tell the truth, not because.
[0:22] Speaker 2: I put my hand on a book and made a.
[0:24] Speaker 1: Wish and working together for a more rational world.
[0:29] Speaker 2: Take the risk of thinking. Feel so much more happiness. Truth,
[0:32] Speaker 2: Fusian wisdom will come to you that way.
[0:35] Speaker 1: Assume nothing, question everything, and start thinking. This is the
[0:43] Speaker 1: Thinking Atheist podcast, hosted by Seth Andrews.
[0:56] Speaker 2: You know how I will often say that this conversations
[1:00] Speaker 2: started on video, and it's on YouTube, but the audio
[1:03] Speaker 2: should be plenty for my podcast listeners. Well, this is
[1:08] Speaker 2: one of those rare occasions where I'm going to say
[1:11] Speaker 2: the audio is fantastic, So enjoy while you're driving around
[1:15] Speaker 2: or whatever. But find a window of time where you
[1:18] Speaker 2: can go back. Click the YouTube link in the description
[1:21] Speaker 2: box and watch the video, because holy cow, we do
[1:26] Speaker 2: a ton of visuals elaborating on what my guest is
[1:30] Speaker 2: referring to. This is one of the longer shows I
[1:35] Speaker 2: have ever released. It pushes an hour and fifty minutes
[1:40] Speaker 2: almost two hours long, but it hums right along. This
[1:44] Speaker 2: is fast, it's furious, it's compelling, it's awesome. And I
[1:48] Speaker 2: hope you learned as much listening and watching as I
[1:51] Speaker 2: did hosting as a former creationist, and I was a
[2:01] Speaker 2: Bible believing, Genesis believing creationist, and I was late to
[2:05] Speaker 2: the evolution party. I got there, but I was late
[2:08] Speaker 2: to the party, you know, and realized I'm a higher
[2:11] Speaker 2: primate related to all living things. But I get overwhelmed
[2:16] Speaker 2: when I try to speak about this verbally, connect the
[2:20] Speaker 2: dots from my ancestors to the modern primate, right, and
[2:25] Speaker 2: you know, the names of the various dig sites and
[2:28] Speaker 2: the fossils discovered, and the versions of pre humans and
[2:33] Speaker 2: all that stuff. I'm like, probably you are. This is
[2:38] Speaker 2: not my wheelhouse. I must lean on the shoulders of giants.
[2:42] Speaker 2: Oh look, I've got one on the line, Erica, who
[2:46] Speaker 2: is host of the Gut Sick Given channel and a
[2:50] Speaker 2: science educator. She was featured on a show I did
[2:54] Speaker 2: a couple of weeks ago. We were talking about mel
[2:55] Speaker 2: Gibson on Joe Rogan, and you know his invocation of
[2:59] Speaker 2: the fake fossil and how this disproves all of paleontoledging apparently. Anyway, Erica,
[3:05] Speaker 2: you are not the hero we deserve today, but you
[3:08] Speaker 2: are the hero we need. Thanks so much for coming.
[3:11] Speaker 2: It's good to show.
[3:12] Speaker 3: It's my pleasure to be here. You know, it depends
[3:15] Speaker 3: on who you are, but you know, the hero I
[3:17] Speaker 3: might actually be a villain to some people out there.
[3:19] Speaker 3: In fact, I know that I am a villain to
[3:21] Speaker 3: some people out there. They don't love the topic that
[3:24] Speaker 3: I'm going to be discussing today. People get really uncomfortable
[3:26] Speaker 3: about this idea of being, you know, a higher primate.
[3:30] Speaker 3: And I put it in quotation marks because you know,
[3:32] Speaker 3: as we'll maybe discuss a little bit like what does
[3:35] Speaker 3: being a higher primate actually mean? Right? Or is there
[3:38] Speaker 3: such thing as being more evolved than something else? It
[3:41] Speaker 3: attends to make people uncomfortable, and it has for quite
[3:44] Speaker 3: some time since the dawn of the discussions of this
[3:47] Speaker 3: kind of thing back in the Enlightenment and even before.
[3:50] Speaker 3: But that being said, there's a gaping hole in most
[3:53] Speaker 3: people's you know, background and education when it comes to
[3:56] Speaker 3: human evolution for the exact reason that I just mentioned, right, people,
[4:00] Speaker 3: we doubt by this idea that we are these clothed
[4:04] Speaker 3: apes that are relatively hairless, and we walk around and
[4:07] Speaker 3: we use these cool technologists and we talk to each other,
[4:09] Speaker 3: and it makes us feel very divorced from the natural world.
[4:12] Speaker 3: But this is all very recent, right, and I truly
[4:15] Speaker 3: do mean recent in time, right, the past couple thousand years.
[4:19] Speaker 3: If you go back just a little bit in time,
[4:21] Speaker 3: the distinguishing factors between us and the other apes that
[4:24] Speaker 3: are still alive today, and indeed, especially as we look
[4:28] Speaker 3: back in time, become slimmer and slimmer and slimmer. Darwin
[4:32] Speaker 3: famously said, man, although as well behaved at best, is
[4:35] Speaker 3: but a monkey shaved. And the case that I'm going
[4:38] Speaker 3: to make today, using the history of these discoveries and
[4:43] Speaker 3: also a couple of don't freak out but anatomical characteristics,
[4:47] Speaker 3: I think can make the case in a way that
[4:49] Speaker 3: anybody can appreciate and sort of relay to the people
[4:53] Speaker 3: in their lives that maybe find this idea kind of
[4:56] Speaker 3: phenomenal that we are, these these animals that have somehow
[5:00] Speaker 3: managed to figure it out. And although I kind of
[5:04] Speaker 3: these days especially intentative and saying that we've got to
[5:06] Speaker 3: figured it out, clearly we're doing something right. So I'm
[5:09] Speaker 3: excited to get into that.
[5:10] Speaker 2: Okay, Well, I know you've got sort of the story
[5:13] Speaker 2: to tell, and I don't want to derail you, but
[5:15] Speaker 2: I do want to set things up with a foundation.
[5:18] Speaker 2: So can we start with some definitions. We talk about
[5:22] Speaker 2: hominins and hominids. Can you define those for us?
[5:27] Speaker 1: Yeah?
[5:27] Speaker 3: Of course, I mean I think you almost need to
[5:29] Speaker 3: go back a little bit more because everybody agrees, for example,
[5:32] Speaker 3: that humans are mammals. Right. We have hair on our bodies,
[5:35] Speaker 3: and the females of our species produced milk. We have
[5:38] Speaker 3: a special type of mandibular joint called the dentary squamosal joint.
[5:43] Speaker 3: We have three inner earbones that let us hear really well,
[5:46] Speaker 3: better than most other critters. But we're also primates, right,
[5:49] Speaker 3: that's a very specific type of mammal. That's our order.
[5:52] Speaker 3: It's slightly more specific, and primates have a bunch of
[5:55] Speaker 3: really cool characteristics that together you can't find in any
[5:59] Speaker 3: other mammal. Right. We have binocular vision we see in
[6:02] Speaker 3: high detail for our foraging and catching you know, prey
[6:05] Speaker 3: like insects, especially for the small little guys. We have
[6:08] Speaker 3: dexterous grasping hands that we can move around in the trees.
[6:12] Speaker 3: We have very mobile bodies overall, again related to that
[6:16] Speaker 3: our boreality, and we've got big brains for our body size,
[6:20] Speaker 3: even with the most primitive of primitive primates like your
[6:23] Speaker 3: lorises and your bush babies and your lemurs and things
[6:26] Speaker 3: like that. But in addition to being primates, we're also
[6:29] Speaker 3: a specific type of primate called haplorine primate, which is
[6:32] Speaker 3: related specifically to a couple of features craniodental features, so
[6:37] Speaker 3: tooth and scully features that we don't have to get into.
[6:40] Speaker 3: But we're also anthropoids, which is which just to say
[6:42] Speaker 3: we're monkeys in general, right, which is something that kind
[6:45] Speaker 3: of freaks people out. Anthropoids two have a bunch of
[6:48] Speaker 3: very specific characteristics that we could get into, but I'm
[6:51] Speaker 3: trying to minimize the amount of horpology that we're discussing.
[6:54] Speaker 3: We're cattarines too, which means we're not just monkeys, we
[6:57] Speaker 3: are old world monkeys. And finally, we are dominids. So
[7:01] Speaker 3: hominid is the term that we use to describe the
[7:03] Speaker 3: great Apes. Now the level above that is homanoid, which
[7:06] Speaker 3: describes all apes. So it's the great apes and the gibbons.
[7:09] Speaker 3: But when you get down to more specific with just hominids.
[7:12] Speaker 3: That's only the great apes. So it includes humans, chimpanzees, gorillas, orangutans,
[7:17] Speaker 3: and bonobos. And that's our little cadre of great apes.
[7:22] Speaker 3: And great apes are defined by a couple of really
[7:25] Speaker 3: interesting factors. Right, Not only do we have big brands
[7:27] Speaker 3: for our body size, but compared to all of their primates,
[7:30] Speaker 3: our brains are enormous for our body size. We take
[7:33] Speaker 3: a long time to grow up, right. We raise our
[7:35] Speaker 3: kids slowly, and we have these long childhoods that take
[7:39] Speaker 3: you a while to learn about the world around us.
[7:42] Speaker 3: And this is a specific type of strategy that some
[7:44] Speaker 3: animals take. You know, grow up slow, have a few kids,
[7:47] Speaker 3: but you've got a much higher likelihood of surviving to
[7:50] Speaker 3: adulthood as compared to the other strategy animals use. We
[7:53] Speaker 3: just have as many kids as possible with the knowledge
[7:55] Speaker 3: that a ton of them are going to die, like
[7:57] Speaker 3: you think, like frogs or fish or things of that nape.
[8:01] Speaker 3: Great apes also have this particular pattern on our molars.
[8:03] Speaker 3: If you open up your jaws and you look back
[8:06] Speaker 3: at your molars, you'll see that they've got five cusps.
[8:08] Speaker 3: That gives you a little Y five pattern, which is
[8:10] Speaker 3: you know, kind of cool apes have obviously no tails.
[8:14] Speaker 3: That's one of the features that defines an a, an ape,
[8:17] Speaker 3: a great ape is that we lack these tails. Of course,
[8:19] Speaker 3: prominoids do too, but you know, keeping in mind what
[8:21] Speaker 3: defines a great ape as well, and we have these short,
[8:25] Speaker 3: stiff lower backs that allow us to move around a
[8:28] Speaker 3: little bit better with more stability up in the trees.
[8:31] Speaker 3: These features define great apes to the exclusion of basically
[8:35] Speaker 3: everybody else, like when they're found all together. Then we
[8:38] Speaker 3: get to what a hominin is. Hominin is our specific lineage.
[8:42] Speaker 3: So when we think about the split between humans and chimpanzees,
[8:45] Speaker 3: and humans and chimps are one another's closest living relatives,
[8:48] Speaker 3: and I should say humans and panin, So the chimps
[8:51] Speaker 3: plus the bonobos, the two types of chimpanzee, they're you know,
[8:54] Speaker 3: really really close together genetically and physically and geographically, et cetera.
[8:59] Speaker 3: But we are ridiculously close to them genetically ninety eight
[9:03] Speaker 3: point eight percent and are coding DNA and about ninety
[9:05] Speaker 3: five ninety six percent when you look at the full genome.
[9:08] Speaker 3: That is more similar than rats are to mice, which
[9:10] Speaker 3: is absolutely mind boggling. It's more similar than lines are
[9:13] Speaker 3: to tigers or African elephants are to Asian elephants, And
[9:17] Speaker 3: it means that humans and chimpanzees are more closely related
[9:21] Speaker 3: than any other like species on plant on the planet
[9:24] Speaker 3: as far as humans go. Humans are more closely related
[9:26] Speaker 3: to chimps than they are to anything else. But also
[9:29] Speaker 3: chimps are more closely related to humans than they are
[9:32] Speaker 3: to anything else to them and bnobos, right, So that
[9:35] Speaker 3: means that if you've got a chimpanzee and you want
[9:37] Speaker 3: to find it's closest living relative, it's not going to
[9:39] Speaker 3: be a gorilla, which is something that people tend to
[9:41] Speaker 3: think think it's like, oh, well, humans are close to chimps,
[9:42] Speaker 3: but chimps are close to guerrillas not so, which is
[9:46] Speaker 3: really interesting to think about. Right, So what we can
[9:48] Speaker 3: do is we can look at the genome of these
[9:50] Speaker 3: two guys and look at the changes between you know,
[9:53] Speaker 3: two living members of each species and try to calculate
[9:56] Speaker 3: when the last common ancestor between the two of us lived.
[10:00] Speaker 3: So you can sort of make a comparison as if
[10:02] Speaker 3: humans and chimps are sister species, then the common ancestor
[10:06] Speaker 3: might be our parent, our mother. So that's the comparison
[10:09] Speaker 3: that you can make between you know, species level family
[10:12] Speaker 3: trees and a human level family tree. So where is
[10:15] Speaker 3: you know, this mother species in time, approximately seven million
[10:20] Speaker 3: years in the past.
[10:22] Speaker 2: You can see why I asked Erica to join us.
[10:25] Speaker 2: It's like a fire hose of information in the face.
[10:28] Speaker 2: And I mean that as a compliment. By the way,
[10:31] Speaker 2: I should have done this at the beginning. But I
[10:33] Speaker 2: know you're people know you're a paleontologist, but can you
[10:36] Speaker 2: do a quick bio intro who you are and what
[10:39] Speaker 2: you do so before we continue our conversation because people
[10:42] Speaker 2: are like, well, obviously that she's she's got some data,
[10:45] Speaker 2: but what's her background?
[10:47] Speaker 3: Yeah, totally, And you know, I want to keep in
[10:49] Speaker 3: mind let everybody know out there that you know, I'm
[10:51] Speaker 3: trying to teach this to you know, in a way
[10:54] Speaker 3: that it's going to be like comprehensible. So there's tons
[10:56] Speaker 3: of little minutia that you know, you could you could
[10:58] Speaker 3: list out as like the of these characteristics that define
[11:01] Speaker 3: like little umps on bones and things like that, and
[11:03] Speaker 3: you know anthropoids as compared to charge your forms or whatever,
[11:06] Speaker 3: but we're leaving those out for today. We're going to
[11:08] Speaker 3: keep it as base level as we can with like
[11:10] Speaker 3: easy to see characteristics that everybody can can recognize. Right.
[11:15] Speaker 3: So my background is I am a fourth year PhD
[11:19] Speaker 3: candidate in biological anthropology. I'm hoping to get the doctor
[11:22] Speaker 3: ate here in the next year, but we'll see. I'm
[11:25] Speaker 3: went on some grants to see if they give me
[11:26] Speaker 3: money to go to Europe and collect some specimens collect
[11:30] Speaker 3: data on some specimens over there. I got my Master's
[11:33] Speaker 3: of Research in Primate Behavior, Biology and Conservation from the
[11:37] Speaker 3: University of Rohampton and I got a BSA, so my
[11:40] Speaker 3: Bachelor's of Science and Arts in pre professional Animal science.
[11:44] Speaker 3: So that was like my bachelor's degree, and I was
[11:47] Speaker 3: on the prevet track, but I ended up pivoting because
[11:49] Speaker 3: I worked at a vet clinic and it was really
[11:51] Speaker 3: bummed me out. I say that every time, but I
[11:53] Speaker 3: think it's worth mentioning. Thank the vets in your life.
[11:55] Speaker 3: Their jobs are not easy. I picked up miners in
[11:58] Speaker 3: biology and in anthropology when I is an undergraduate, and
[12:01] Speaker 3: I basically go yearly to Kenya to collect data at
[12:06] Speaker 3: the museum there and on, you know years. For the
[12:09] Speaker 3: past several years, I've been going out and doing field
[12:11] Speaker 3: work in West kenyat a side called Koru, So I
[12:14] Speaker 3: look for Miocene Aibe fossils, which incidentally are the guys
[12:17] Speaker 3: that lived right before that split between humans and chimpanzees.
[12:21] Speaker 2: Two more definitions. If you'll indulge me, I'm a Homo sapien.
[12:27] Speaker 2: Flash that out for me. Homo sapien. What are we
[12:30] Speaker 2: talking about?
[12:31] Speaker 3: Yeah, so, Homo sapiens means you know, wise man, of
[12:34] Speaker 3: course it does, right, like we give ourselves the name
[12:36] Speaker 3: more like, well, we're the wisest of all the animals.
[12:38] Speaker 3: And this was on my Linaeus back in the seventeen hundreds,
[12:41] Speaker 3: you know, the father of taxonomy and a creationist himself.
[12:44] Speaker 3: And I bring this up specifically because basically everybody was
[12:47] Speaker 3: creationist at the time of Linnaeus. When you know naturalism
[12:51] Speaker 3: and this, this sort of budding, burgeoning field of being
[12:54] Speaker 3: a gentleman naturalist was coming to light. And Linnaeus, for
[12:57] Speaker 3: all his wisdom knew, recognized that humans were in fact
[13:02] Speaker 3: most closely allied with other apes. And so what he
[13:04] Speaker 3: did when he was classifying humans into our species, Homo sapiens,
[13:08] Speaker 3: is he created a higher level category called anthropomorpha. You know,
[13:11] Speaker 3: the man like animals, and he pulled all of the
[13:14] Speaker 3: other apes up into Anthipomorpha, basically saying that you know,
[13:16] Speaker 3: we're we're humans, we're the wise men, and these guys
[13:19] Speaker 3: are like us. They're close, but they're they're not quite
[13:21] Speaker 3: there yet. And this actually made a lot of people
[13:24] Speaker 3: kind of mad because they were like, well, humans are
[13:26] Speaker 3: made in the image of God like. You can't say
[13:27] Speaker 3: that they're man like. That's like saying like they're godlike.
[13:30] Speaker 3: And Linaeus was like, well, I don't know what to
[13:32] Speaker 3: tell you, because I've dissected a billion of these things
[13:34] Speaker 3: and they have all of the characteristics that we have.
[13:37] Speaker 3: And what I mean when I say that is that Linnaeus,
[13:40] Speaker 3: being the father of taxonomy, invented that classification scheme that
[13:43] Speaker 3: you see kingdom, phylum, class order, family, genus, species. It's
[13:47] Speaker 3: basically a way by which we organize life on our
[13:50] Speaker 3: so that we can discuss it. And it's in a
[13:52] Speaker 3: nested system, so species is more specific, that genus, genus
[13:56] Speaker 3: is more specific than family, and so on and so forth,
[13:58] Speaker 3: and there are a lot of little mini categories that
[14:01] Speaker 3: can fit in between there, but species is your most
[14:03] Speaker 3: specific categorization, and for us. That's almost sapiens. Our genus
[14:08] Speaker 3: is Homo, our family is Hamenidae, the hominids, as we
[14:11] Speaker 3: discussed earlier. And so when we're communicating what a species is,
[14:16] Speaker 3: or a group of animals that are that belong to
[14:19] Speaker 3: a specific species, it usually has a set of characteristics
[14:22] Speaker 3: that defines it to the exclusion when they're found altogether
[14:25] Speaker 3: of absolutely everything else. So humans as a species today
[14:29] Speaker 3: have a ton of characteristics that only humans have today.
[14:32] Speaker 3: We have huge brains, we walk by ped lee, we
[14:35] Speaker 3: have little teeth and little jaws, things of that nature.
[14:39] Speaker 2: One more and then I'm going to let you do
[14:41] Speaker 2: your thing. I don't mean to you know, I don't want.
[14:42] Speaker 3: To put the I want this to be more of
[14:45] Speaker 3: a backlab.
[14:45] Speaker 2: Okay, good, good. Well, you know I've heard the word
[14:48] Speaker 2: species many times from you. But if we get into
[14:51] Speaker 2: the creationist, especially the Young Earth creationist, can ham At
[14:55] Speaker 2: answers and Genesis talks about species versus kinds, which is
[14:59] Speaker 2: supposed to help the explain how all of the Earth's
[15:02] Speaker 2: animals were represented on Noah's Arc. Is Kind's a thing
[15:06] Speaker 2: in science? Erica?
[15:08] Speaker 3: No kind is not a thing in science, And all
[15:11] Speaker 3: you need to do to see this is to look
[15:13] Speaker 3: at their literature. You don't even need to look at
[15:16] Speaker 3: what actual science says. And mostly this is because actual
[15:20] Speaker 3: science is not talking about kinds. We left creationism in
[15:24] Speaker 3: the dust and the Enlightenment truly, and a lot of
[15:27] Speaker 3: people don't talk about this. But a lot of this
[15:28] Speaker 3: is because of the work of Christian scientists from the
[15:31] Speaker 3: day who were like, yeah, this isn't going to work.
[15:34] Speaker 3: Creationists don't know their history, but they don't know a
[15:36] Speaker 3: lot of things. So kind is generally a very vague,
[15:39] Speaker 3: higher order classification that includes a bunch of different animals
[15:43] Speaker 3: that are related to one another. They are okay with
[15:46] Speaker 3: those guys being related through common descent because Seth, As
[15:50] Speaker 3: you probably know, creationists don't have a problem with evolution
[15:54] Speaker 3: by natural selection. They have a problem with taking that
[15:57] Speaker 3: back in time to its inevitable conclusion, which is common
[16:00] Speaker 3: descent from a single common ancestor. That's where they have
[16:03] Speaker 3: their little bugaboo. So they're cool with saying that species
[16:05] Speaker 3: can change over time. And you know, in that way
[16:08] Speaker 3: they say that Noah, God creates all these kinds in
[16:11] Speaker 3: the beginning, and then of course the global flood happens,
[16:13] Speaker 3: and during this global flood. God tells Noah to take
[16:15] Speaker 3: two of every kind of animal onto the arc, and
[16:18] Speaker 3: the art can only be so big. And we know
[16:20] Speaker 3: how big it was according to the Bible, because they
[16:23] Speaker 3: give us the dimensions, a very inconvenient fact to creation,
[16:26] Speaker 3: it's in general. But because we have those dimensions, we
[16:29] Speaker 3: know how many critters can actually fit on that arc.
[16:32] Speaker 3: And because we have the fossil record, we know that
[16:34] Speaker 3: there are like billions of species that have exists over time.
[16:37] Speaker 3: So they can't have every two of every kind of
[16:39] Speaker 3: species come on that arc, which is why they broadened
[16:41] Speaker 3: up what kind can be. And so, for instance, today
[16:44] Speaker 3: answers and Genesis will say that all the cats share
[16:46] Speaker 3: a kind, and all of the cats are related to
[16:49] Speaker 3: each other, but none of them are related to, say dogs,
[16:52] Speaker 3: or all the dogs are related to one another, but
[16:53] Speaker 3: none of the dogs are related to, say bears, and
[16:56] Speaker 3: so on and so forth. And the problem with this
[16:58] Speaker 3: is that we have animals that bridge those kinds and
[17:02] Speaker 3: the fossil record and also living today. And their answer
[17:05] Speaker 3: to that is of course to just say, well, that's
[17:07] Speaker 3: its own kind too. That the biggest inconvenience comes when
[17:11] Speaker 3: they look to the apes, right, because humans, again, as
[17:13] Speaker 3: I said earlier, are most closely rated to chimps and
[17:15] Speaker 3: vice versa, so they can't say that humans and himps
[17:19] Speaker 3: are the same kind. That ruins their entire narrative that
[17:22] Speaker 3: the humans are the especially created, unique animals. And for
[17:25] Speaker 3: the record, can Hand thinks humans should belong to a
[17:27] Speaker 3: separate kingdom. He doesn't even think we're animals, which is
[17:30] Speaker 3: farther than any naturalist, no matter how creationists they are,
[17:33] Speaker 3: has ever gone in the history of biology. Right, Linnaeus
[17:37] Speaker 3: didn't do this. Richard Owen didn't even do this. He
[17:40] Speaker 3: accepted that people were mammals at least Kenham's crazy. We
[17:44] Speaker 3: know that to be a case though anyway. So they
[17:46] Speaker 3: needed this category to be broad enough to include the
[17:50] Speaker 3: fewest amount of animals to fit onto that boat, and
[17:52] Speaker 3: then also diversify and explain modern biodiversity today, and humans
[17:58] Speaker 3: present this this. Humans and chimps present massive roadblock to
[18:01] Speaker 3: that because genetically we are so similar to one another
[18:05] Speaker 3: that if you separate humans and chimps into separate kinds,
[18:08] Speaker 3: then you have to separate lions and tigers into separate kinds,
[18:11] Speaker 3: and African and Aesian elephants into separate kinds and rats
[18:14] Speaker 3: and mice into separate kinds, and that is too many
[18:16] Speaker 3: animals to fit on that little boat.
[18:19] Speaker 2: I was in a conversation I'll never forget this a
[18:22] Speaker 2: few years ago, and I was talking about the human
[18:23] Speaker 2: animal right or primates, we are animals, and the Christian said,
[18:29] Speaker 2: or we're not animals, we're mammals, or we're not animals.
[18:33] Speaker 2: I want to speak to that for me Erica, you
[18:35] Speaker 2: want to go, yeah.
[18:36] Speaker 3: Yeah, I mean it's one of those things where it's
[18:38] Speaker 3: like people don't understand that this is where education, our
[18:42] Speaker 3: education system, at least here in the States, has failed
[18:44] Speaker 3: them because they don't understand that these categories that we
[18:47] Speaker 3: assign as I alluded to earlier, are nested within one another.
[18:51] Speaker 3: So all chimpanzees or pantroglidities are members of the genus pan.
[18:56] Speaker 3: All members of the genus pan are members of the
[18:58] Speaker 3: family Pmenidae or the great apes. All grade apes are primates,
[19:03] Speaker 3: All primates are mammals, All mammals are coordates, All coordates
[19:09] Speaker 3: are animals, and all animals are eukaryos. Right, It's like
[19:13] Speaker 3: a little Russian nesting doll. If you occupy a smaller
[19:17] Speaker 3: Russian nesting doll that is within a bigger one. Everything
[19:21] Speaker 3: that's within that smaller matrishka doll is also in that
[19:25] Speaker 3: bigger one by its very definition. So you can't say
[19:28] Speaker 3: something is a mammal without it being an animal. Every mammal,
[19:32] Speaker 3: because it is nested within anamalia, is an animal. Every
[19:36] Speaker 3: primate is a mammal. Every ape is a primate. Every
[19:41] Speaker 3: grade ape is an ape. Right Like, it doesn't matter
[19:45] Speaker 3: how you do it, You're routed by the very system
[19:48] Speaker 3: that a creation is developed to organize God's creation. That
[19:52] Speaker 3: was his specific goal in the night or in the
[19:54] Speaker 3: seventeen hundreds.
[19:57] Speaker 2: Okay, enough of the preliminaries to the break. We're going
[20:00] Speaker 2: to go back in time millions and millions and millions
[20:04] Speaker 2: of years to talk about the first human traits in
[20:07] Speaker 2: non human primates so long ago. Hang on, My guest
[20:18] Speaker 2: today is a biological anthropologist and an expert in the
[20:21] Speaker 2: origins of human kind. But when did humans start becoming humans?
[20:28] Speaker 2: That's where our conversation picks up here. Okay, So I'm
[20:35] Speaker 2: a non scientist and I try to look back through
[20:38] Speaker 2: time and I keep thinking when, and this is my
[20:42] Speaker 2: desire for a simplistic answer which I know doesn't exist.
[20:45] Speaker 2: But when did it happen? When did this split happen?
[20:47] Speaker 2: When did we come to a fork in the road
[20:49] Speaker 2: when I was something else, some kind of a quadruped thing,
[20:52] Speaker 2: or I had fans or gills, I mean, I don't know,
[20:55] Speaker 2: and then there's like it was there a fork, and
[20:56] Speaker 2: all of a sudden I began the road toward being
[20:59] Speaker 2: the evolved primemate that I am seth.
[21:03] Speaker 3: This speaks to a really important concept and evolution that
[21:05] Speaker 3: a lot of people don't get, which is that evolution
[21:08] Speaker 3: doesn't have a goal. It's easy in retrospect to see
[21:10] Speaker 3: where these forks happened, but in real time, evolution isn't
[21:13] Speaker 3: trying to create anything. It's a filtration process. And I
[21:18] Speaker 3: think we have to define what evolution is. It's change
[21:20] Speaker 3: over time, that's it. And you know, intrinsically linked to
[21:24] Speaker 3: this is that if species can diverge, if new species
[21:27] Speaker 3: can form from a parent species, Now, if you take
[21:30] Speaker 3: that back in time, mathematically everything will converge on a
[21:34] Speaker 3: single common ancestor, just like a family trade. Right. That's
[21:40] Speaker 3: It's a very simple concept. And that changeover time can
[21:42] Speaker 3: be morphologically or physically. The physical characteristics that we have,
[21:46] Speaker 3: and I'm going to be using the word morphology probably
[21:48] Speaker 3: a little bit in this conversation. It's just your physical
[21:50] Speaker 3: characteristics and also genetically or across your genome that change
[21:55] Speaker 3: over time is happening. You know, obviously it both except
[21:58] Speaker 3: when it happens in your genome, it happens physically as well.
[22:01] Speaker 3: So you know, you ask when this happens. That you
[22:03] Speaker 3: could pick a time period, any of them, and look
[22:06] Speaker 3: at where our ancestors were at that time, because by necessity,
[22:10] Speaker 3: we have an ancestor at any point in time, going
[22:12] Speaker 3: back to the first life on earth, the last common
[22:15] Speaker 3: ancestor of everything living today. But I think for our
[22:18] Speaker 3: purposes today, we'll start with when we split from chimps,
[22:21] Speaker 3: because that's when things really start to get interesting from
[22:24] Speaker 3: a perspective of what makes us human and what makes
[22:27] Speaker 3: us a human animal, right, what makes us an ape?
[22:31] Speaker 3: And when we look at the molecular clock, that tells
[22:35] Speaker 3: us that that happened about seven million years ago, seven
[22:39] Speaker 3: million years in the past. And you know, the molecular clock,
[22:41] Speaker 3: as I said earlier, is just looking at the differences
[22:43] Speaker 3: between humans and chimps and sort of taking that back
[22:46] Speaker 3: in time. So evolution, then if it applies to humans.
[22:49] Speaker 3: And Darwin addressed this exact same flipp and question back
[22:54] Speaker 3: in the eighteen hundreds, first when he published Origin in
[22:57] Speaker 3: eighteen fifty nine, and then again when he published Ascent
[22:59] Speaker 3: of Man in eighteen seventy one. And when he published
[23:02] Speaker 3: Origin he didn't mention humans but one time, and all
[23:05] Speaker 3: he said in the entire book, and it's a very
[23:07] Speaker 3: dense book, is that light will be thrown on the
[23:10] Speaker 3: origin of Man. And so when people read Origin, of
[23:12] Speaker 3: course what they took away was, oh, my gosh, this
[23:14] Speaker 3: is a phenomenally elegant means by which to explain how
[23:19] Speaker 3: organisms survive and change over time. And then the other
[23:22] Speaker 3: immediately after thought was wait, does this apply to humans?
[23:27] Speaker 3: Because unannowns to a lot of creationists, right, is at
[23:29] Speaker 3: that time people accepted that humans were animals, but we
[23:32] Speaker 3: believed ourselves at specially endowed animals, that animal's only in
[23:36] Speaker 3: physical sense, right, And so Darwin, you know, makes this prediction.
[23:41] Speaker 3: He effectively says, well, you know, if humans evolved from
[23:45] Speaker 3: more basal apes, we should see that morphologic or physical
[23:50] Speaker 3: change over geologic time. So if we expect this morphologic
[23:54] Speaker 3: change over geologic time from this generic ape right that
[23:58] Speaker 3: comes before, and we're becoming more specific. Humans are still apes,
[24:01] Speaker 3: but we're getting more specific to prominance and then Homo sapiens.
[24:04] Speaker 3: What does that morphologic change look like. Well, we could
[24:07] Speaker 3: look at chimpanzees, which is what people did in the
[24:10] Speaker 3: first place, like Darwin and Huxley and Lenaeus before they
[24:13] Speaker 3: did in the first place, and they look at humans
[24:15] Speaker 3: and hips. What makes us different. There's two main things
[24:18] Speaker 3: that separate humans from all other living apes and in
[24:21] Speaker 3: fact from the apes that lived prior to seven million
[24:23] Speaker 3: years ago, and that's big brains and bipedalism. By pedalism
[24:27] Speaker 3: means walking on two legs. We're the only ape. We're
[24:30] Speaker 3: the only primate that has these huge, gigantic brains for
[24:33] Speaker 3: our body size, even for an ape and even for
[24:36] Speaker 3: a primate. And we also walk weird. Right, all these
[24:39] Speaker 3: other guys and they hang out in the trees, they
[24:41] Speaker 3: walk on fist. When they come to the ground, they
[24:43] Speaker 3: walk on their palms, or they walk on their knuckles.
[24:45] Speaker 3: We walk on two feet and we do it all
[24:47] Speaker 3: the time, which is very weird. It's an odd way
[24:50] Speaker 3: to move. Really, the only other animals that do this
[24:53] Speaker 3: obligately or because they have to. Is like birds, you know,
[24:56] Speaker 3: Other than that, it's mostly just us. It's a weird
[24:58] Speaker 3: way of walking. And so so I'm going to boil
[25:00] Speaker 3: it down to these two characteristics. We should see if
[25:03] Speaker 3: human evolution is legitimate morphologic change over geologic time in
[25:07] Speaker 3: that brain should get bigger, and we should start to
[25:09] Speaker 3: see apes stand up and walk around on two feet. Fortunately,
[25:14] Speaker 3: both of those things are recorded in your bones. Right.
[25:17] Speaker 3: A chimpanzee can't walk by pudi lee for its entire life,
[25:20] Speaker 3: it gets pathologies. And humans can't walk quadrupuedly for our
[25:23] Speaker 3: whole lives or else we get pathologies. And we know
[25:25] Speaker 3: this because there have been humans who have done that,
[25:27] Speaker 3: and there have been circus chimpanzees who have been trained
[25:30] Speaker 3: to walk upright, and they do it for their whole
[25:32] Speaker 3: lives and then they die young. Which is to say,
[25:34] Speaker 3: we know when the morphologic characters demand a certain type
[25:37] Speaker 3: of movement. So what do we see, right, we set
[25:40] Speaker 3: the stage, We know what needs to change over time,
[25:42] Speaker 3: we know when it needs to change over time, and
[25:44] Speaker 3: we know when it starts. So when we go back
[25:46] Speaker 3: to seven million years ago, what do we find, well,
[25:48] Speaker 3: in the year two thousand, we discovered a hominin that's
[25:51] Speaker 3: been named say helanthropist hidensis. Now say hellanthropist chedensis, for
[25:54] Speaker 3: all intents and purposes, looks apish, right. It's this little
[25:58] Speaker 3: pin head. It's got a teeny tiny little brain really
[26:00] Speaker 3: no bigger than a chimpanzee, and it's got that chimpanzee
[26:03] Speaker 3: face with that big snout and this huge brow ridge. Overall,
[26:07] Speaker 3: it's nothing write home about. In fact, when they first
[26:09] Speaker 3: pulled it up, some people were like, oh, it's it's
[26:10] Speaker 3: like a chimpanzeester. That's kind of cool. But then you
[26:14] Speaker 3: flip it over and when you look at the underside
[26:16] Speaker 3: of this thing, you can see that the foramen magnum,
[26:20] Speaker 3: this is the hole at the base of the skull
[26:22] Speaker 3: where your spinal cord comes out, is pushed forward compared
[26:26] Speaker 3: to that of a chimpanzee, and it looks more like
[26:28] Speaker 3: that of a human. And that's really important because where
[26:31] Speaker 3: your spine, where your spinal cord comes out at the
[26:34] Speaker 3: base of your skull, determines how you hold your head.
[26:36] Speaker 3: If it's pushed forward, that means that your head sits
[26:39] Speaker 3: upright on your spinal column like that, and if it
[26:42] Speaker 3: comes out at the back. It looks it's more a
[26:44] Speaker 3: sort of like a slant like that, and that implies
[26:46] Speaker 3: that you're walking on all fours at some point your
[26:48] Speaker 3: your knuckle walking around, and it demands that position and
[26:53] Speaker 3: that corresponding locomotion. Right, you think about your dog, your
[26:57] Speaker 3: dog's frame, and magnum is in the very back of
[26:58] Speaker 3: its skull right approximate link right here. If you're all
[27:01] Speaker 3: tried to stand up and walk on two feet like that,
[27:04] Speaker 3: its head is cranked upward all the time. It's not sustainable.
[27:07] Speaker 3: It literally could not move in that way without again
[27:10] Speaker 3: developing pathologies. So that forwardly placed for a monognmum suggests
[27:14] Speaker 3: to us that Saintalanthropist S. Cendensis was holding its head
[27:17] Speaker 3: upright more like a human than like pretty much any
[27:21] Speaker 3: other Miocene ape that came before it. And in addition
[27:23] Speaker 3: to that, it also has little canine teeth and both
[27:26] Speaker 3: males and females, which is pretty unusual for other apes,
[27:30] Speaker 3: with the exception of gibbons. Because the males compete for
[27:33] Speaker 3: access to females, they tend to have bigger can nine teeth,
[27:35] Speaker 3: not by much in chimps and bonobo's, but by a lot.
[27:38] Speaker 3: And like irrealism chips. So they look at this thing
[27:41] Speaker 3: and they're like, Okay, theoretically, as you move back to
[27:44] Speaker 3: that common ancestory between humans and chimps, the difference between
[27:47] Speaker 3: the first on the human line and the first on
[27:49] Speaker 3: the chimp line, those things should be almost identical. Really,
[27:53] Speaker 3: the characters that define them as on the chimp line
[27:55] Speaker 3: or the human line should be so scanned. And when
[27:58] Speaker 3: we look at san aalanthropist cheddentza, we find like the
[28:00] Speaker 3: scantest of the scant frame and magnums a little bit forward,
[28:03] Speaker 3: canine tooth is a little bit small. And then they
[28:06] Speaker 3: decided to get some dates on this thing. And the
[28:09] Speaker 3: date that came back for sale Anthropus judensis found in
[28:11] Speaker 3: Chad in the year two thousand is seven million years ago.
[28:14] Speaker 3: Like dead on with that molecular clock.
[28:17] Speaker 2: Let me jump in, hang on, let me jump in
[28:19] Speaker 2: real fast, and I'm going to play a little metal
[28:21] Speaker 2: Gibson riff here. How do you know that? And this
[28:24] Speaker 2: is usually when they say carbon dating, which just like, well,
[28:27] Speaker 2: that's the wrong measuring tool, right, But how do you
[28:29] Speaker 2: know seven million years? How do you get there?
[28:32] Speaker 3: Yeah, I mean that's that is a phenomenal question. So
[28:35] Speaker 3: Radiometric dating is the means by which we typically glean
[28:39] Speaker 3: ages for fossils. And we combined radiometric dating with the
[28:42] Speaker 3: law of superposition, which was developed by geologists during the
[28:46] Speaker 3: Enlightenment Hutton and Lyle and folks like that. So basically,
[28:50] Speaker 3: you know, if I may, if I may pull out
[28:53] Speaker 3: my whiteboard seth oh.
[28:54] Speaker 2: Oh yeah, yeah, visual aids. I'm all about that.
[28:58] Speaker 3: Yeah, I think I think it's I think it should.
[29:00] Speaker 3: We'll use pink like that color. So let's say the
[29:06] Speaker 3: let me make sure we would do an all the
[29:07] Speaker 3: layer there. Let's say this is our geologic column, right,
[29:12] Speaker 3: the geologic column deposits and layers. Everybody can agree on that,
[29:16] Speaker 3: and at various levels in the geologic column you find
[29:19] Speaker 3: fossils and rocks and things of that nature all throughout it. Right,
[29:24] Speaker 3: The law of superposition tells us that the lower layers
[29:27] Speaker 3: were deposited first and are thus older than the upper layers.
[29:31] Speaker 3: All you have to do to see this is get
[29:33] Speaker 3: one of those sand toys and shake it up and
[29:34] Speaker 3: let the sand deposit, and you'll see that this is
[29:37] Speaker 3: true every single time. What that means, too, is that
[29:40] Speaker 3: the fossils that you find down here are older than
[29:43] Speaker 3: the fossils that you find up here. Now, what's really
[29:46] Speaker 3: cool about this is the law of superposition can give
[29:48] Speaker 3: you the relative age of fossils, but to find the
[29:51] Speaker 3: absolute age of fossils and of layers themselves, you need
[29:55] Speaker 3: to use radiometric dating. So radiometric dating it relies on
[29:59] Speaker 3: one thing that the laws of physics are constant as
[30:02] Speaker 3: we move backwards through time. It relies on the fact
[30:05] Speaker 3: that amongst the the isotopes within rocks, like rocks contain elements,
[30:11] Speaker 3: elements come in various isotopes. When we look at these isotopes,
[30:16] Speaker 3: some isotopes are stable and some are unstable. Unstable isotopes
[30:20] Speaker 3: will spontaneously decay into a more stable version of themselves.
[30:24] Speaker 3: This is what we see in everything. We see this
[30:26] Speaker 3: phenomenon in chemistry as well. Right, things want to be stable,
[30:29] Speaker 3: so they you know, I say want like they desire it. Yeah,
[30:33] Speaker 3: they want to be stable. They want to they want
[30:36] Speaker 3: to move to a more stable state, so they spontaneously
[30:39] Speaker 3: decay into more stable version of themselves. What that means
[30:43] Speaker 3: is that if you can tell the rate at which
[30:45] Speaker 3: unstable isotopes become stable isotopes, if you know the rate
[30:49] Speaker 3: at which that happens, which we do because we've tested
[30:51] Speaker 3: it a zillion times in the lab. You can take
[30:53] Speaker 3: any given rock, you can look at the ratio of
[30:56] Speaker 3: stable to unstable isotopes, and you can take that back
[30:59] Speaker 3: into to when it was all unstable, right, the amount
[31:02] Speaker 3: of time that it would have taken for all of
[31:04] Speaker 3: those now stable versions of that isotope to be their
[31:07] Speaker 3: unstable counterpart, and that will tell you the age at
[31:10] Speaker 3: which that rock formed. Does that make sense?
[31:13] Speaker 2: It does, it doesn't. My next question is are there
[31:16] Speaker 2: different types of radiometric dating? I know, carbon dating is
[31:19] Speaker 2: good to a certain pretty shallow depth of time, and
[31:22] Speaker 2: then there are others that you use for dinosaurs, et cetera.
[31:25] Speaker 2: So are there different types of tests?
[31:28] Speaker 3: Yeah, there are tons, dozens, right, and you can corroborate
[31:31] Speaker 3: them with non radiometric means. So carbon dating is great
[31:34] Speaker 3: for recent stuff. It's pretty good up until about fifty
[31:37] Speaker 3: or sixty thousand years into the past. But if you
[31:40] Speaker 3: want to go really deep in time for things like fossils,
[31:42] Speaker 3: you need like uranium, lead or are gone oregone. And
[31:46] Speaker 3: the reason they all have two elements is because you're
[31:49] Speaker 3: talking about the relationship between the unstable and the stable right,
[31:52] Speaker 3: the rate at which uranium decays into lead, the rate
[31:55] Speaker 3: at which you know, I forget which isotope of ar
[31:58] Speaker 3: on it is, but the unstable isotoe of argent decays
[32:00] Speaker 3: into the stable version of art of argon. Right. And
[32:03] Speaker 3: so there are a bunch of different methods of radiometric
[32:06] Speaker 3: dating that you can use to look at these these
[32:10] Speaker 3: ratios within these rock layers, and you can test them
[32:13] Speaker 3: against other types of radiometric dating, or you can test
[32:17] Speaker 3: them against things like ice cores right, the rate at
[32:20] Speaker 3: which ice deposits in you know, the Arctic and the Antarctic.
[32:24] Speaker 3: You can look at the relationship between or the dates
[32:27] Speaker 3: between radiometric dating and how fast tree rings form, or
[32:31] Speaker 3: you could do you could compare it to thermoluminescent dating.
[32:34] Speaker 3: You could compare it to the rate at which the
[32:36] Speaker 3: continents move apart from one another, because you know, the
[32:40] Speaker 3: clock starts ticking for this decay of unstable into stable.
[32:44] Speaker 3: They start doing. That became once the rock is formed,
[32:46] Speaker 3: Meaning you can go to these places in the Earth
[32:48] Speaker 3: where new rock is forming and being pushed out because
[32:51] Speaker 3: of the movement of the continents, and you can compare
[32:53] Speaker 3: the age that you get along that movement to the
[32:56] Speaker 3: origin point of those rocks and the rate at which
[33:00] Speaker 3: those rocks are moving outwards using satellite data, right, they match.
[33:05] Speaker 3: They shouldn't match. The rate at which the continents move apart,
[33:08] Speaker 3: and the rate at which unstable isotopes decay to stable isotopes,
[33:11] Speaker 3: those should not match one another. If the Earth isn't
[33:13] Speaker 3: very ancient, it's really truly phenomenal support for the notion
[33:18] Speaker 3: that the Earth is super duper old. And people appreciated
[33:22] Speaker 3: this without even the advent of radiometric dating. Again in
[33:25] Speaker 3: the Enlightenment, Charles Lyell and James Hutton before him, and
[33:28] Speaker 3: all of their geology friends, they knew the Earth was
[33:31] Speaker 3: old because they looked at the world around them, like
[33:33] Speaker 3: the White Cliffs of Dover right or the formation of
[33:36] Speaker 3: the Red Sea, and they said, this kind of stuff
[33:39] Speaker 3: happens slowly today. So in order to explain the formation
[33:42] Speaker 3: that we have today, you have to go really far
[33:45] Speaker 3: in the past. If it's working the same way today
[33:47] Speaker 3: as it did in the past. So with that understanding
[33:50] Speaker 3: of radiometric dating, right, a fossil isn't made up of
[33:53] Speaker 3: the right type of rock to radiometrically date You can
[33:56] Speaker 3: only radiometrically date igneous rocks because igneous rocks are the
[33:59] Speaker 3: type of rocks that form in volcanoes, meaning you know
[34:02] Speaker 3: when that you know the composition of that rock with
[34:05] Speaker 3: relative certainty, whereas with metamorphic rock or sedimentary rock, you
[34:09] Speaker 3: can't be sure. It's usually composed of several different types
[34:12] Speaker 3: of rocks, meaning when you radiometrically data, you're not sure
[34:14] Speaker 3: which part of the rock you're dating. That's why you
[34:16] Speaker 3: need igneous rock to date. So what that means is
[34:18] Speaker 3: that you can't typically date the fossil themselves, right. I
[34:21] Speaker 3: can't take a sample off of say heillanthropist genensis and
[34:24] Speaker 3: run it, you know, through a mass spectrometer and try
[34:26] Speaker 3: to rhdiometrically data try to get an age for that thing.
[34:29] Speaker 3: So what you need to do is you need to
[34:30] Speaker 3: date the layers that the fossil is found in. So
[34:32] Speaker 3: let's say say hilanthropist Genensis is right here in this
[34:35] Speaker 3: little layer that I'm working with my expo marker here.
[34:38] Speaker 3: What we can do is we can date either this
[34:41] Speaker 3: layer itself, right if there's ash in that layer, or
[34:44] Speaker 3: if there isn't, we can date the closest ash layer
[34:47] Speaker 3: above and below it. So let's say this ash layer
[34:50] Speaker 3: is six point nine to nine million years old and
[34:54] Speaker 3: this ash layer here is seven point zh one million
[34:59] Speaker 3: years old. When we know that sejal Anthropus shidensis is
[35:01] Speaker 3: found in the layer in between these two that we
[35:03] Speaker 3: could radiometrically date, so we know that it's in between
[35:07] Speaker 3: six point nine to nine and seven point oh one
[35:09] Speaker 3: million years old, You know, seven million years old?
[35:12] Speaker 2: Was it you who said, ironically that many of the
[35:15] Speaker 2: creationists who say that radiometric dating is false rely on
[35:19] Speaker 2: the oil and gas industry, which uses types of dating
[35:23] Speaker 2: to do what it does. Like, our sciences use this
[35:26] Speaker 2: all the time and they accept it over here, but
[35:28] Speaker 2: not when it comes to primates in the age of
[35:30] Speaker 2: the Earth. Is that right?
[35:31] Speaker 3: Oh yeah, right, Like we require radiometric dating to base
[35:36] Speaker 3: and model. Right, So when we drill for oil, you
[35:38] Speaker 3: don't just want to drill in a random spot. If
[35:40] Speaker 3: you drill in a random spot, you're wasting money because incidentally,
[35:44] Speaker 3: it costs a lot of money to operate a drill
[35:46] Speaker 3: that is capable of breaking into an oil deposit. So
[35:50] Speaker 3: you want to be really careful about where you set
[35:52] Speaker 3: that drill down. And we know based off of looking
[35:55] Speaker 3: at all of the rocks in the world that some
[35:57] Speaker 3: formations from some time period are more oil or natural
[36:02] Speaker 3: gas rich than others. So for instance, the Permian is
[36:05] Speaker 3: great for natural gas. You can go to the Carboniferous
[36:08] Speaker 3: for coal. These time periods need to be you know,
[36:11] Speaker 3: isolated in formations, Like if you come across a formation,
[36:14] Speaker 3: you want to model that basin to find out if
[36:16] Speaker 3: it's the right type of rock the right time to
[36:19] Speaker 3: drill there and see if you see what you can find.
[36:21] Speaker 3: So what they do is they send geologists out to
[36:23] Speaker 3: areas that might be rich in these natural resources to
[36:27] Speaker 3: basin model. They model the basin, and the way that
[36:29] Speaker 3: they do that is they radiometrically date the rocks. So
[36:32] Speaker 3: if you if you've got this idea of oh, you know,
[36:33] Speaker 3: there might be oil over here, Let's say I'm a geologist,
[36:35] Speaker 3: you send me out there. I'm going to radiometrically date it.
[36:38] Speaker 3: I'm gonna characterize the basin with index fossils, et cetera.
[36:41] Speaker 3: And then if I come back and I say, it's
[36:42] Speaker 3: got all the little tiny microfossils of the carboniferous and
[36:46] Speaker 3: it's dated to you know, hundreds of millions of years
[36:48] Speaker 3: or during the time period that the carbonifers took place.
[36:51] Speaker 3: You can drill here, you're probably gonna find, you know, coal,
[36:54] Speaker 3: You're probably gonna find the coal same here. And this
[36:58] Speaker 3: is a multi trillion dollar industry that, ironically is the
[37:03] Speaker 3: These oil and gas companies are often held by people
[37:07] Speaker 3: who are Bible believing Christians, right, but of course they
[37:10] Speaker 3: rely on radiometric dating and the implicit ideas that go
[37:13] Speaker 3: along with that, you know, namely being the ancient age
[37:16] Speaker 3: of the Earth to actually carry out their jobs. There
[37:19] Speaker 3: was a Young Earth creation soil industry seth. It's called
[37:23] Speaker 3: Zion Oil and Gas. Guess how wealthy they are.
[37:30] Speaker 2: Okay, I'm going to come back to when I say
[37:33] Speaker 2: the dawned of Man. I always think about the first
[37:34] Speaker 2: fifteen minutes of Stanley Kubrick's two thousand and one, you know,
[37:38] Speaker 2: but I always think about that Victorian era illustration, the
[37:43] Speaker 2: Marcher Progress. It shows the ape and then you see
[37:46] Speaker 2: more upright, and then there's a biped and then you
[37:48] Speaker 2: see a man in a business suit. And this is
[37:50] Speaker 2: supposed to be the progression of human beings. That's total bullshit,
[37:54] Speaker 2: is that right? Yeah?
[37:54] Speaker 3: Completely Evolution isn't linear, right, A family tree isn't linear.
[37:59] Speaker 3: It's not you know, your grandma becoming your mom becoming you. Right.
[38:03] Speaker 3: You have these descendants that split off in their own
[38:05] Speaker 3: directions and are subject to the forces of evolution, to
[38:08] Speaker 3: the mechanisms of evolution, natural selection, genetic drift, gene flow,
[38:12] Speaker 3: their own mutations, and so they become their own species. Well,
[38:15] Speaker 3: what this means is that you don't have a line
[38:17] Speaker 3: that represents evolution. You have a branching pattern. You have
[38:20] Speaker 3: a tree, which means that at various points in time,
[38:23] Speaker 3: there weren't just the human ancestor the human hominin, the
[38:27] Speaker 3: one that was on the trajectory to us. There were
[38:30] Speaker 3: dozens of other hominins that lived and eked out their
[38:33] Speaker 3: own living and lived for in some cases millions of
[38:37] Speaker 3: years successfully as an animal goes, and we just happen
[38:41] Speaker 3: to be the only ones left, which is why it
[38:43] Speaker 3: feels linear and why it was depicted as linear.
[38:46] Speaker 2: So seven million years and then is there a what's
[38:49] Speaker 2: the next to say it? Erica, the next step or
[38:52] Speaker 2: the next evolution in towards us today?
[38:56] Speaker 3: Yeah, I mean so I'll tell you too. You know,
[38:58] Speaker 3: Saltenensis is Countra Brusil among some, namely because it's a
[39:02] Speaker 3: crushed skull, so it's difficult to know for sure whether
[39:06] Speaker 3: or not I tend to buy the location of the
[39:07] Speaker 3: frame and magnum I think it's it's I think it's
[39:10] Speaker 3: a hominin. I think that the reduction the canth and
[39:12] Speaker 3: the location of that hole at the base of the
[39:15] Speaker 3: skull can can tell us that it's at least something
[39:17] Speaker 3: that's relatively close to hominin, right insofar as we have
[39:22] Speaker 3: characteristics that define a hominin. And there are people who
[39:25] Speaker 3: have issues with the dates as well, namely because it
[39:27] Speaker 3: was a surface fine, so let's say that you don't
[39:30] Speaker 3: buy it, right Like, Let's say you're like, no sale,
[39:32] Speaker 3: Dipers sends this. I don't think that that's the first hominin, right,
[39:36] Speaker 3: And remember that the human characteristics that we're looking for
[39:38] Speaker 3: are steps towards bipedalism and big brains. Just for today, again,
[39:43] Speaker 3: there's a ton of little mini ones. Let's just say
[39:45] Speaker 3: we're looking at those two and we're going to skip
[39:47] Speaker 3: over a roar in because I don't have a skull
[39:48] Speaker 3: for it, So we're going to go to the next
[39:50] Speaker 3: one that I have a cranium, for which is Aartipithecus
[39:53] Speaker 3: rabbitus at four point four million years old. And both
[39:56] Speaker 3: of these guys, for the record, they're found in Africa.
[39:59] Speaker 3: So this ramitus is super interesting for a couple of reasons.
[40:03] Speaker 3: It's my favorite hominin actually. So you look at it,
[40:06] Speaker 3: and first of all, it's a wonderful fossil, right, you
[40:09] Speaker 3: look at this, this cranium, here, this skull, and you
[40:12] Speaker 3: notice that you've got a lot of material here on
[40:14] Speaker 3: the right side and less material on the left. But
[40:17] Speaker 3: the nice thing about hominin's and then I think about
[40:19] Speaker 3: virtually all mammals, all mammals if i'm you know, unless
[40:22] Speaker 3: I'm missing like a weirdo somewhere, is that we're bilaterally symmetric.
[40:26] Speaker 3: And a lot of creationists don't understand this. But what
[40:28] Speaker 3: this means is that if you have the right side
[40:31] Speaker 3: of the fossil, you know what the left side looks
[40:33] Speaker 3: like too. Right, I don't need to have this part
[40:35] Speaker 3: of the brow ridge to know that this that looks
[40:39] Speaker 3: like this right. You could just take the right side
[40:40] Speaker 3: and reflect it over onto the left. And this means
[40:44] Speaker 3: that when you find a fossil, you've actually usually got
[40:46] Speaker 3: a lot more of it complete than you might think,
[40:48] Speaker 3: because you just you reflect it over and then you
[40:51] Speaker 3: know you can connect the gaps in between. There's only
[40:54] Speaker 3: so many ways that you know, a zygomatic arch here
[40:57] Speaker 3: can can complete itself. Right, I have this part sticking
[40:59] Speaker 3: out here anteriorly or towards the front, and then I
[41:02] Speaker 3: have this part sticking out here posteriorly or towards the back.
[41:05] Speaker 3: It's not going to come out and do a loopy loop,
[41:07] Speaker 3: you know, let's get to connect in the middle. So
[41:10] Speaker 3: in this way we tend to have a lot more
[41:12] Speaker 3: of fossils than we, you know, appreciate at face value.
[41:15] Speaker 3: So Artipithecus ramitis was discovered in the nineteen nineties, but
[41:18] Speaker 3: it wasn't published on until two thousand and nine. Tim
[41:20] Speaker 3: White and colleagues sat on it for a really long time,
[41:23] Speaker 3: and it's this wonderful skeleton. So in the case of
[41:26] Speaker 3: a lot of fossils in general, you'll have partial you know, remains, teeth,
[41:30] Speaker 3: bits and pieces of skulls, bits and pieces of long bones.
[41:33] Speaker 3: But it's really really rare and wonderful to find partial skeletons.
[41:37] Speaker 3: And that means, you know, when you got the skeleton
[41:39] Speaker 3: more than just the skull. That can tell you a
[41:41] Speaker 3: lot more about how it moved. So the first thing
[41:43] Speaker 3: you want to do when you look at at Ardipithecus
[41:45] Speaker 3: ramitis is assess it for our two traits. Does it
[41:47] Speaker 3: have a big brain. Nope, it's a total pinhead, the
[41:49] Speaker 3: little teeny tiny brain, just like we would expect for
[41:52] Speaker 3: something very early on in human evolution, something very you know,
[41:56] Speaker 3: chimpy looking kind of. But when you flip it over
[42:00] Speaker 3: that frame and magnum is forward again, and it is
[42:03] Speaker 3: unambiguously forward right because you've got the connection of these
[42:06] Speaker 3: bones all up the side there. It can't be anywhere
[42:09] Speaker 3: else other than right here. What that means is already
[42:11] Speaker 3: sat with its head directly on top of that vertebra column,
[42:15] Speaker 3: standing at least upright, with a posture more similar to
[42:17] Speaker 3: humans than any great ape, any other great ape. But
[42:21] Speaker 3: in addition, Artipithecus ramitus has part of the pelvis preserved.
[42:25] Speaker 3: Human pelvis are really weird, they're really unique, and they're
[42:29] Speaker 3: directly related to how we move. An animal that walks
[42:31] Speaker 3: on all fours is a really different pelvis than an
[42:33] Speaker 3: animal that walks on on two legs like us and
[42:36] Speaker 3: The pelvis in general can be broken up into three bones,
[42:39] Speaker 3: the ilium, the issium, and the pubis. In humans, that
[42:42] Speaker 3: top part of the pelvis, the ilium, is really short,
[42:45] Speaker 3: and the bottom part of the issum is also really short.
[42:47] Speaker 3: And the reason that both of them are short is
[42:49] Speaker 3: because we pack gluteal muscles on the side, and that's
[42:51] Speaker 3: what helps us stay upright right, stand upright, and get
[42:54] Speaker 3: on one leg. You know, if you're watching this video
[42:56] Speaker 3: or just you know, anywhere where yours on your alli,
[42:58] Speaker 3: driving or something, and you'll immediately feel your glutes activate
[43:01] Speaker 3: to make sure that you can balance and stay up right.
[43:04] Speaker 3: We use our gluts to run, We use our glutes
[43:05] Speaker 3: to walk for long distances. Chimps have really weak glutes,
[43:08] Speaker 3: but ours are powerful. We need that short, outwardly flaring
[43:12] Speaker 3: ilium to pack those muscles on. So when you compare
[43:14] Speaker 3: a human and a chimp, they're both really short so
[43:16] Speaker 3: you can you can pack them outwards. We're in chimpanzees,
[43:19] Speaker 3: they're really long because they're more like these thin slabs
[43:21] Speaker 3: and already pithecus ramitous. The top part of the pelvis,
[43:25] Speaker 3: the ilium is short like a human's, but the issium
[43:28] Speaker 3: is still kind of long. It's literally transitional in a
[43:32] Speaker 3: part of a collection of bones. You couldn't ask for
[43:36] Speaker 3: a cooler transitional fossil part of the bone or the
[43:38] Speaker 3: collection of bones is looks like a human, looks more
[43:41] Speaker 3: like a human, and part of it looks like a chimp.
[43:44] Speaker 3: So it's got that anterior frame and magnum, and it's
[43:46] Speaker 3: starting to get that pelvis that looks more like a
[43:49] Speaker 3: human as compared to previous hominants at four point four
[43:52] Speaker 3: million years ago. If you see this hominin right that
[43:56] Speaker 3: has some characteristics that are that are more modern in
[43:59] Speaker 3: some care terristics that are more primitive, and the ones
[44:02] Speaker 3: that are more modern are related to walking upright, you
[44:04] Speaker 3: can naturally ask the question, well, why would it change
[44:06] Speaker 3: to move upright? And I think that the answer that
[44:09] Speaker 3: is intuitive to a lot of people is well, it
[44:12] Speaker 3: probably came out of the trees. It probably had to
[44:14] Speaker 3: be on the ground. More so, what do we see
[44:16] Speaker 3: when we look at the environment in which this hominin
[44:19] Speaker 3: and which Arnipithecus ramitis lived. Paleon anthropologists argue that when
[44:22] Speaker 3: you run a paleo environmental analysis on its habitat, use
[44:27] Speaker 3: a mixed woodland which means that it was clusters of
[44:29] Speaker 3: trees separated by wide open spaces. Arnipithecus ramitis would have
[44:33] Speaker 3: needed to be at least capable walking upright, which is
[44:36] Speaker 3: actually a more efficient way of walking than walking on
[44:38] Speaker 3: all fours as far as metabolic expenditure goes. It would
[44:42] Speaker 3: have needed to be more efficient moving from tree cluster
[44:45] Speaker 3: to tree cluster to collect fruits.
[44:47] Speaker 2: Okay, So if I'm understanding Erica, then the primates that
[44:52] Speaker 2: were on the plains, and they were I don't know,
[44:55] Speaker 2: better at surviving on the plains, adapting, procuring resources, reproduce
[45:00] Speaker 2: on the planes, they would have been the ones then
[45:03] Speaker 2: more to reproduce, which created more bipeds. Am I tracking?
[45:08] Speaker 3: Yeah, imagine a rainforest right where say, hell Anthropis chidensis,
[45:12] Speaker 3: this guy and the likes of it are living, and
[45:14] Speaker 3: they're upright in the trees like some apes are even today.
[45:18] Speaker 3: Gibbons are upright when they're in the trees, and when
[45:20] Speaker 3: they come down to the ground they run bi pedal ly,
[45:22] Speaker 3: although they're really really bad at it, and the rest
[45:24] Speaker 3: of their anatomy corresponds with something that it's very apish.
[45:28] Speaker 3: They don't have the pelvis that looks like ours. They
[45:30] Speaker 3: don't have an S shaped spine, they don't have a
[45:33] Speaker 3: toe that's in line with the rest of their toes,
[45:35] Speaker 3: they don't have a valdous knee. All these little characteristics
[45:38] Speaker 3: that make a biped a biped. Gibbons have one of them,
[45:40] Speaker 3: and it's a slightly more anterior frame and magne because
[45:42] Speaker 3: they're upright in those trees. But what happens when you
[45:45] Speaker 3: have an ape that's upright in the trees and then
[45:48] Speaker 3: the trees go away, you get an ape that's upright
[45:51] Speaker 3: on the ground. Remember what I said about those forward
[45:53] Speaker 3: frame and magnums. If that form and magnum is forward,
[45:56] Speaker 3: you can't be a quadruped right, You're going to be
[45:58] Speaker 3: looking down at the ground all the time. So if
[46:00] Speaker 3: it's upright in the trees so it can hold its
[46:02] Speaker 3: arms directly above its head to move around, when those
[46:04] Speaker 3: trees go away, it is necessarily going to be walking
[46:07] Speaker 3: up right on the ground, which means that there is
[46:09] Speaker 3: immediately as these trees start to disappear, a massive selection
[46:13] Speaker 3: for apes that are capable of moving efficiently and quickly
[46:16] Speaker 3: upright when they're on the ground. The ones that can't
[46:19] Speaker 3: are getting killed off. You're not capable of getting food,
[46:21] Speaker 3: you know, they're dying of starvation and dehydration and things
[46:24] Speaker 3: like that. But the ones that are slightly more advantage
[46:27] Speaker 3: towards efficient bipedalism when they do come down to the ground,
[46:31] Speaker 3: are going to experience that selection pressure to move even
[46:34] Speaker 3: more in that direction. And the more important bone between
[46:37] Speaker 3: the ilium and the issum for maintaining that bipedality, especially
[46:40] Speaker 3: early on, is the ilium. It's the one that we
[46:42] Speaker 3: would expect to change first, and it's the one that does.
[46:46] Speaker 2: So we're at four points whatever million years when happens
[46:49] Speaker 2: next Erica.
[46:50] Speaker 3: Yeah, we're four point four million years and you've got
[46:52] Speaker 3: an ape that's capable of walking bipedally on the ground,
[46:55] Speaker 3: but it's really really awkward when it's doing so. The
[46:58] Speaker 3: trees are present, but they're going away as the Miocene
[47:01] Speaker 3: draws to a close and the Pliocene comes to fruition, right,
[47:05] Speaker 3: this is going to be the rise of the grasslands
[47:07] Speaker 3: in places like Africa. After Artipithecus bramidus, we see the
[47:12] Speaker 3: rise of the Australopiths. Ostelopiz is a sort of group
[47:16] Speaker 3: that contains all of the members of Astrolopithecus, so Osceolopithecus
[47:20] Speaker 3: is an enormously specios genus. What that means is that
[47:23] Speaker 3: there are a ton of different species and specimens that
[47:26] Speaker 3: belong to Astrolopithecus the genus, and Osteolopithecus is a genus
[47:30] Speaker 3: is just wickedly fascinating. So I'll pull down Oslopithecus Africanus here,
[47:36] Speaker 3: this is Missus Pleas, a famous fossil cranium from South
[47:40] Speaker 3: Africa and where Artipithecus was found. Just in the east.
[47:45] Speaker 3: Oslopithecus starts is spread out into a bunch of different regions.
[47:48] Speaker 3: In part it is argued with the expansion of those grasslands.
[47:52] Speaker 3: Now when we look at Ostelopithecus, we're really fortunate, right.
[47:56] Speaker 3: Everybody knows Ostelopithecus through Lucy, who is discovered in the
[47:59] Speaker 3: nineteenth by Johansen and colleagues. And when she was first discovered,
[48:04] Speaker 3: here's the reason she's called Lucy is because they were playing,
[48:06] Speaker 3: you know, the Beatles, Lucy in the Sky with Diamonds
[48:08] Speaker 3: on their record player and when they discovered her, so
[48:11] Speaker 3: they call her Lucy. And she's a female, so you know,
[48:13] Speaker 3: Lucy makes sense. But when you look at Lucy, we
[48:17] Speaker 3: see a massive change Lucy being an australopith and these
[48:19] Speaker 3: characteristics exist in all members of Australopithecus, which is, you know, well,
[48:23] Speaker 3: although I'm showing you missus plaz here, that's just because
[48:25] Speaker 3: this is a really nice cranium to show you some
[48:28] Speaker 3: characteristics of Australopithecus. Lucy is going to be the individual
[48:32] Speaker 3: specimen that changes the game, because, like Artiepithecus, it's not
[48:35] Speaker 3: just a cranium, it's a skeleton. When we look at Lucy,
[48:39] Speaker 3: we see a couple of really, really really important things. Seth,
[48:43] Speaker 3: Can I ask you what would you expect of a
[48:45] Speaker 3: hominin that lives now fully on the grasslands, right or
[48:48] Speaker 3: at least you know, for the most part in these
[48:50] Speaker 3: grassland environments? Would you expect What would you expect her
[48:53] Speaker 3: to look like? With regard to efficiency on two legs?
[48:57] Speaker 2: Oh gosh, I don't know. I mean to be able
[49:00] Speaker 2: to walk effectively, to be able to have enough brain
[49:04] Speaker 2: capacity to procure resources. I don't know what should I expect?
[49:10] Speaker 3: No, you nailed it. I mean it's intuitive, right If
[49:13] Speaker 3: being bipedal is the more efficient way of moving and
[49:16] Speaker 3: you're predisposed to being bipedal, and your trees are disappearing,
[49:20] Speaker 3: you would expect that by the time virtually all the
[49:22] Speaker 3: trees are gone, you better be really good upright, You
[49:25] Speaker 3: better be a really good biped What you predicted is
[49:27] Speaker 3: exactly what we found when we looked at Lucy from
[49:30] Speaker 3: the neck down. Her morphology, the physical characteristics are basically
[49:35] Speaker 3: just a slightly worse version of what we see in humans.
[49:38] Speaker 3: And when I say slightly worse, I mean with regard
[49:40] Speaker 3: to walking and running. She was really good at what
[49:42] Speaker 3: she did, and I'll get to that at a moment.
[49:44] Speaker 3: But the characteristics that make humans by pedal, as I
[49:47] Speaker 3: said earlier, are that forwardly placed frame and magnum the
[49:49] Speaker 3: whole of the basis the skull and as shaped spines
[49:52] Speaker 3: that we can hold our bodies upright, a valgus knee
[49:55] Speaker 3: or a knee that comes in at an angle again
[49:57] Speaker 3: to help you bear our weight and transfer that way
[50:00] Speaker 3: over a bull shaped pelvis, and then remember that short
[50:03] Speaker 3: ilium and short issum to pack those gluteal muscles on
[50:06] Speaker 3: the sides. And specific characteristics with regard to the feet,
[50:11] Speaker 3: so the big tone needs to be in line so
[50:12] Speaker 3: you can roll that weight through and toe off, and
[50:16] Speaker 3: you need to have three arches in the foot so
[50:18] Speaker 3: that when you take those big hard steps while you're
[50:20] Speaker 3: walking or running, shock is absorbed through your body. Right,
[50:23] Speaker 3: Chimpanzees don't have any of those characteristics. Artiepithecus has a few,
[50:28] Speaker 3: namely a fourthly blaze frame and magnum in a short ilium,
[50:31] Speaker 3: But by the time we reach aus Tolopithecus seth all,
[50:34] Speaker 3: the characteristics for bipedalism are there, again, just a slightly
[50:37] Speaker 3: worse version of what we see in humans. When we
[50:39] Speaker 3: look at Lucy, her pelvis is reminiscent in breath taking
[50:46] Speaker 3: detail of the humans. The ilium is short these human
[50:49] Speaker 3: is short. She would have been able to pack those
[50:50] Speaker 3: gluteal muscles on the side. She has a valgus knee
[50:52] Speaker 3: and knee that comes inward in an angle so that
[50:55] Speaker 3: she could hold her body sort of in a bright
[50:56] Speaker 3: column and effectively transfer that weight over her frame. And
[50:59] Speaker 3: magnum is sort of infertile on the basis of other
[51:01] Speaker 3: ostlopiths that also have her characteristics, so you know that
[51:04] Speaker 3: you're looking at the same type of animal. It's horridly placed.
[51:08] Speaker 3: When you look at Oslopithicus africanas here it's directly forward right,
[51:12] Speaker 3: certainly not what you see in something like a chimpanzee.
[51:15] Speaker 3: So that leaves the question, Okay, well, from Lucy's skeleton,
[51:17] Speaker 3: we could see that she's got the right kind of knee,
[51:19] Speaker 3: she's got the right kind of pelvis, she's got the
[51:21] Speaker 3: right kind of skull, right again, inferring from other osclopids
[51:26] Speaker 3: that we had. But what about the feet, Because something
[51:28] Speaker 3: that creationists do you complain about all the time is
[51:30] Speaker 3: that Lucy didn't have any feet. There were no footbones
[51:33] Speaker 3: associated with Lucy. And that's correct, and this was something
[51:36] Speaker 3: that creationis is the time lashed onto and they still
[51:38] Speaker 3: latch onto it today even though they shouldn't for reasons
[51:41] Speaker 3: that I'll mentioned in the second. But there's this wonderful
[51:44] Speaker 3: story about another we're pretty close by geographically team that
[51:50] Speaker 3: was working near where Lucy was discovered in East Africa,
[51:54] Speaker 3: and it's actually the Leaky's right. They're hanging around in
[51:58] Speaker 3: old de Vai Gorge like around the old of Vie
[52:00] Speaker 3: Gorge sight, and the story goes that that they're you know,
[52:02] Speaker 3: ending the day they've been looking for fossils. They would
[52:05] Speaker 3: be the ones that would discover the first specimens of
[52:08] Speaker 3: parenthropists as well as will Parenthpus boisey, as well as
[52:12] Speaker 3: Genus Homo, the very early members of Genus Homo. But
[52:15] Speaker 3: at the time they're they're just kind of screwing around.
[52:17] Speaker 3: They're they're ending their day, getting ready to head back
[52:19] Speaker 3: to camp, and the story goes that they start to
[52:21] Speaker 3: have a dung a dung fight. Right. So, I don't
[52:23] Speaker 3: know if you've ever seen elephant poop seth, but it's
[52:25] Speaker 3: very fleaky, you know, like kind of like dirt clouds,
[52:30] Speaker 3: you know. So they start throwing dirt clods, except it's
[52:32] Speaker 3: poop at each other. And the story goes that that
[52:36] Speaker 3: Mary Leaky, she comes over the corner and she's kind
[52:38] Speaker 3: of like hiding, you know, behind a ridge, and you know,
[52:42] Speaker 3: they they look down that the team is all kind
[52:43] Speaker 3: of looking down as they're hiding, and one of the
[52:45] Speaker 3: teammates shouts out to Mary and and it's like, we
[52:48] Speaker 3: need to stop. We found something. If re member sures
[52:51] Speaker 3: I think he was actually one of the Tanzania workers.
[52:53] Speaker 3: So they all stop. They walk over there and there's
[52:56] Speaker 3: a track way of footprints cemented in the ground and
[52:59] Speaker 3: when you look at these footprints. You Marry remarked these
[53:03] Speaker 3: really human, but they weren't human. They were too small
[53:07] Speaker 3: to be human. And the morphology, even at first glance
[53:10] Speaker 3: was just slightly off right. It was just slightly abern
[53:14] Speaker 3: the big toast, just a little bit off to the side,
[53:16] Speaker 3: there's just the heel print is really really deep. So
[53:18] Speaker 3: they start to investigate these prints, and you know, the
[53:20] Speaker 3: site that they're actually at would come to be known
[53:22] Speaker 3: as Laate Totally. These are the late Totally footprints. So
[53:25] Speaker 3: what's fascinating about these prints is they tell us a
[53:29] Speaker 3: lot about the lives that these ostralopids led. So we're
[53:31] Speaker 3: in East Africa, so this is this is gonna be
[53:33] Speaker 3: Lucy's species, Chilopithecus afarensus, and this would be this would
[53:36] Speaker 3: come to be known once they radiometrically dated the site
[53:39] Speaker 3: that these are. This is the same time as Oschelopathagus
[53:42] Speaker 3: afarensus lived. And when you look at these footprints, we
[53:45] Speaker 3: u see two individuals walking side by side. The smaller
[53:48] Speaker 3: set of footprints is sort of walking, you know, bow
[53:51] Speaker 3: legged like that, with each foot pointing outward, and the
[53:54] Speaker 3: larger set of princess walking straight on. This is really
[53:57] Speaker 3: cool because by the time these footprints were discovered, we
[53:59] Speaker 3: were starting to pick up on the fact that Oscilopithecus
[54:01] Speaker 3: is a genus. There are big versions and there are
[54:04] Speaker 3: small versions of even you know, within species of Austerlopithus
[54:08] Speaker 3: like afforensis suggesting that these guys were sexually dimorphics. The
[54:10] Speaker 3: males were bigger than the females by quite a bit,
[54:13] Speaker 3: more closer to gorillas than like humans today. So if
[54:16] Speaker 3: these footprints match those expectations, the males are cute like
[54:19] Speaker 3: twice the size of the females, which is a smaller one.
[54:21] Speaker 3: And the way that we know that it's probably a
[54:24] Speaker 3: female and not just a kid, which is you know,
[54:26] Speaker 3: inevitably your next question is because you get that pattern
[54:29] Speaker 3: of those feet sort of tilting out to the side
[54:32] Speaker 3: when an individual today, like if you test women today
[54:35] Speaker 3: when they're carrying something on their hip, right, so when
[54:37] Speaker 3: you're carrying a load on your hip, you tend to
[54:39] Speaker 3: blow your legs out like that sort of account for
[54:42] Speaker 3: that asymmetry in how you're bearing your way. So you know,
[54:46] Speaker 3: why would an australopiths be carrying something on their hip?
[54:48] Speaker 3: What could they be carrying? Well, chimpanzee babies hold onto
[54:51] Speaker 3: their mom's backs. But what happens when you have, you know,
[54:54] Speaker 3: a mom that isn't horizontal like this, they're vertical like
[54:58] Speaker 3: this or walking up bright You can't hold onto the
[55:01] Speaker 3: back anymore. You're a little baby, we're your muscles. You
[55:03] Speaker 3: can't just cling, So the mom has to hold the baby,
[55:07] Speaker 3: you know, holding it on her hips as she walks.
[55:11] Speaker 3: That's the argument that's made. When you look at the
[55:13] Speaker 3: mail that's walking side by side with her, you can
[55:15] Speaker 3: see that there's a smaller set of tracks inside the
[55:18] Speaker 3: Mail's footprints. And the argument has been made in the
[55:21] Speaker 3: past that this is another this is another chlopith, and
[55:24] Speaker 3: that it's a kid like following along behind, you know,
[55:27] Speaker 3: the these two adults. It reminds me of when I
[55:30] Speaker 3: was a little kid, you know, walking in the snow.
[55:32] Speaker 3: I grew up in the Midwest, and when my dad
[55:34] Speaker 3: and I would be out in the snow, he'd be
[55:35] Speaker 3: taking these big steps and I would be walking inside
[55:37] Speaker 3: his steps because it's easier than you know, walking and
[55:40] Speaker 3: paving my own pat Being a little kid and the
[55:42] Speaker 3: snow's really high, you might be asking, well, what are
[55:45] Speaker 3: they walking in? And The way that they dated this
[55:47] Speaker 3: site was through an ash layer because this massive knick eruption,
[55:50] Speaker 3: you know, approximately three point four million years earlier, had
[55:54] Speaker 3: covered this region of East Africa in ash. You know,
[55:57] Speaker 3: it was quite deep ash. And so it wasn't just
[55:59] Speaker 3: ochlopid foot prints that they found, but it was all
[56:01] Speaker 3: sorts of different animal footprints. And the nice thing about
[56:03] Speaker 3: ash layers is you can date them directly. You can
[56:05] Speaker 3: radiometric with date them directly because they have tiny little
[56:09] Speaker 3: igneous rocks inside them in the ash layers. So what
[56:12] Speaker 3: we had with this, with this trail of footprints was
[56:15] Speaker 3: you know, ostensibly a little family walking along in an
[56:20] Speaker 3: ash layer and going from point A to point B.
[56:23] Speaker 3: And I think that's really familiar and really human sounding. Right.
[56:27] Speaker 3: It could be that they all walked separately, They walked
[56:31] Speaker 3: on the first, the big male comes from the female
[56:33] Speaker 3: an hour later, and then you know, a kid afterwards,
[56:35] Speaker 3: and that they weren't walking all as a group. But
[56:39] Speaker 3: I think that that doesn't match. What we seem to
[56:42] Speaker 3: be learning more and more about these guys is that
[56:44] Speaker 3: they were, you know, they were social just like us.
[56:46] Speaker 3: They would have been in groups, they would have been together,
[56:49] Speaker 3: especially if disaster had struck like this. So then you
[56:52] Speaker 3: look at these footprints, right, they got three arches, and
[56:55] Speaker 3: the toe is almost as in line as in a human,
[56:58] Speaker 3: not quite, but it's close. And the way that they
[57:00] Speaker 3: bore their weight, even though they had these three arches,
[57:03] Speaker 3: just like a modern human, is intermediate in between chimpanzees
[57:08] Speaker 3: and humans. It's transitional and it's transitional and the way
[57:11] Speaker 3: that it bears its weight. And the way that they
[57:12] Speaker 3: discovered this is they took cast of the late totally
[57:14] Speaker 3: footprints and then they took cast of chimpanzee footprints today,
[57:18] Speaker 3: and then they had hunter gatherers with no shoes make
[57:21] Speaker 3: trackways in some synthetic ash, and they took cast of those,
[57:24] Speaker 3: and then they compared the linear and then GM measurements.
[57:28] Speaker 3: They did a GM analysis on these three sets of footprints,
[57:31] Speaker 3: and they found that lay Totally was in between. So
[57:33] Speaker 3: even though the morphology of the foot looks more like
[57:36] Speaker 3: a human than like a chimp, the way that it's
[57:37] Speaker 3: bearing its weight is still intermediate, right, and it's more
[57:41] Speaker 3: towards a human, but it's still sort of more in
[57:44] Speaker 3: the middle than the morphology itself. And then you might
[57:47] Speaker 3: being well, how Okay, the creationist comes and says, okay,
[57:50] Speaker 3: so we got these footprints. How do you know that
[57:51] Speaker 3: the lost Elpithecus made those footprints? Right? What if they
[57:53] Speaker 3: were just modern human footprints made three point four million
[57:56] Speaker 3: years ago? And actually it wasn't that long ago. It
[57:58] Speaker 3: was six thousand years ago. And you know, drawing the
[58:01] Speaker 3: connection between Oschlopithecus afarensis and these footprints is is not
[58:04] Speaker 3: a fair thing to do, even though they were found
[58:06] Speaker 3: really close to one another within a geographic sense. And
[58:10] Speaker 3: you know to that, I say again, we have the
[58:12] Speaker 3: feet of these things, a phenomenal specimen called Little Foot
[58:16] Speaker 3: or STW five seventy three, this skeleton, and you're gonna
[58:19] Speaker 3: put a picture here set and when you go back
[58:21] Speaker 3: and look at this, you're gonna be like, oh my god,
[58:23] Speaker 3: I didn't even know we had skeletons that complete. It's
[58:25] Speaker 3: like a complete skeleton of Ostcholopithecus africanus, a member of Oscolopithecus,
[58:30] Speaker 3: and it matches like the morphology that we have matches
[58:33] Speaker 3: what we have of every other Oscholopiths. Remain in the big,
[58:37] Speaker 3: big characteristics of the bones that we have, and we
[58:39] Speaker 3: have the remains of over three hundred individuals from this genus.
[58:44] Speaker 3: So what this tells us is that one we've been
[58:46] Speaker 3: correct in assigning all of those others to Oscolopithecus. But
[58:49] Speaker 3: the nice thing about this particular specimen is that part
[58:52] Speaker 3: of the foot is preserved and it's like a single chunk.
[58:55] Speaker 3: It's like still articulated, and it tells like, when you
[58:58] Speaker 3: look at the remains of this individual skeleton's foot, that
[59:02] Speaker 3: toe is in line, right, it looks like the type
[59:05] Speaker 3: of footprint that would have left the late totally prints.
[59:07] Speaker 3: Not that the human prints are not a good match
[59:09] Speaker 3: for late totally, this foot is suggesting that again we
[59:13] Speaker 3: were correct, as we all tend to be, in assigning
[59:16] Speaker 3: that footprint trail to Australopithagis. And of course because we
[59:19] Speaker 3: have this entire like skeleton from a different member of Austrolopithecus,
[59:23] Speaker 3: but an ostelopith nonetheless, we can check what we said
[59:25] Speaker 3: about Lucy. Does the entire genus have those characteristics that
[59:28] Speaker 3: we originally said. Yes, it has the interior freeme and magnum,
[59:32] Speaker 3: It has the bull shaped pelvis, it has the valgus knee,
[59:34] Speaker 3: it has the s shaped spine. Right, it has the
[59:37] Speaker 3: right foot morphology. Again, it's more primitive or basal versions
[59:40] Speaker 3: of those of what we see in a human, but
[59:42] Speaker 3: they're there. This thing could not have been a quadruped
[59:45] Speaker 3: when it came onto the ground, right, It had to
[59:47] Speaker 3: have been by pedal, and its anatomy tells us that
[59:50] Speaker 3: it was by pedal. A lot.
[59:54] Speaker 2: More than forty minutes left in this compelling conversation. Again,
[59:57] Speaker 2: the YouTube link is in the description box of the show.
[1:00:01] Speaker 2: As we move closer and closer to the modern age
[1:00:05] Speaker 2: and modern humans, we're going to talk more about just
[1:00:08] Speaker 2: how we evolved next, continuing my conversation with Erica, who
[1:00:21] Speaker 2: is probably best known as gut Sick Given science educator
[1:00:25] Speaker 2: and host of the Gut Sick Given YouTube channel. Okay,
[1:00:30] Speaker 2: so I'm gonna just want to like recap real fast.
[1:00:32] Speaker 2: We're talking about, for lack of a better word, to split.
[1:00:35] Speaker 2: We begin to see characteristics that we can recognize in
[1:00:39] Speaker 2: humans in primates seven million years ago. Am I tracking?
[1:00:43] Speaker 2: There were they primates at that point?
[1:00:45] Speaker 3: Oh? Yeah? Yeah? Because remember said all apes are primates,
[1:00:49] Speaker 3: all of them, right, All monkeys are primates, All lemurs
[1:00:52] Speaker 3: are primates. Not all primates are apes, right, Lemurs are apes,
[1:00:56] Speaker 3: but they all nest within primates generally, so you're dead
[1:00:59] Speaker 3: on when you say that we see the first characteristics
[1:01:01] Speaker 3: of a hominin. So the human specific line seven million
[1:01:05] Speaker 3: years ago.
[1:01:06] Speaker 2: What about geography, Is this a specific part of the
[1:01:09] Speaker 2: world that we're seeing a focused area.
[1:01:12] Speaker 3: Yeah, it's all in. It's all in Africa. These first
[1:01:16] Speaker 3: prominences are showing up in East and South Africa and
[1:01:19] Speaker 3: a little bit in Central.
[1:01:20] Speaker 2: We are all Africans. I always like that whenever you
[1:01:23] Speaker 2: meet a racist, you know, you're always like, maybe you
[1:01:25] Speaker 2: want to do a genetic test on yourself though. Okay,
[1:01:29] Speaker 2: So then if we skip forward a few million years,
[1:01:32] Speaker 2: we're talking about primates quadrupeds in the trees. When the
[1:01:35] Speaker 2: trees begin to disappear and their more flat lands, we
[1:01:38] Speaker 2: then the ones who are more optimized for bipedalism and
[1:01:43] Speaker 2: have larger brains to be able to survive without the trees,
[1:01:46] Speaker 2: without the shelter of the trees, et cetera. Those are
[1:01:49] Speaker 2: the ones who begin to pro create and we begin
[1:01:51] Speaker 2: to see bipedalism. The order of the day. Is that close?
[1:01:56] Speaker 3: Yeah, yes, it's pretty close. Let me let me like
[1:01:59] Speaker 3: specified a little bit. So I want to ask you
[1:02:01] Speaker 3: a question, because you're good at this, you've already you
[1:02:03] Speaker 3: made a mistake. So let's say let's say you've got
[1:02:07] Speaker 3: a rainforest, right, and you know there's a rainforest seven
[1:02:10] Speaker 3: million years ago, and in this rainforest you have two
[1:02:12] Speaker 3: apes living there, two species of apes. One of the
[1:02:14] Speaker 3: apes is a quadruped in the trees, so what walks
[1:02:17] Speaker 3: on all fours on top of the branches. And then
[1:02:19] Speaker 3: one of the apes is upright in the trees, so
[1:02:22] Speaker 3: it hangs below the branches like this. If you take
[1:02:25] Speaker 3: away the trees, which of those two apes, the quadruped
[1:02:28] Speaker 3: or the upright one in the trees, is going to
[1:02:30] Speaker 3: be more predisposed to being upright.
[1:02:33] Speaker 2: On the ground, the one who is predisposed to be
[1:02:36] Speaker 2: upright in the trees, right, exactly.
[1:02:38] Speaker 3: Yeah, if you have an ape that's upright in the
[1:02:40] Speaker 3: trees and you take away the trees, it's going to
[1:02:41] Speaker 3: be upright on the ground. We see this today, Gibbons,
[1:02:44] Speaker 3: and I'll give you a picture here. When they come
[1:02:46] Speaker 3: down from the trees, even though they live in the
[1:02:48] Speaker 3: trees like for their entire lives, pretty much, when they
[1:02:50] Speaker 3: do come down, they have to walk upright. So if
[1:02:53] Speaker 3: you have an ape that's upright in the trees, which
[1:02:55] Speaker 3: is like an advantageous way to move around in the trees,
[1:02:58] Speaker 3: because you hang below, you swing arm over all arm,
[1:03:00] Speaker 3: you break eate. If you take away those trees are
[1:03:02] Speaker 3: upright on the ground. So what you're seeing, the argument goes,
[1:03:05] Speaker 3: and there are many hypotheses about these, is the one
[1:03:07] Speaker 3: that I like the best. If you have a rainforest
[1:03:10] Speaker 3: in Africa and at the end of the Miocene the
[1:03:12] Speaker 3: force starts to go away, You've got a bunch of
[1:03:14] Speaker 3: different types of apes living in these trees. Some of
[1:03:16] Speaker 3: them are upright in the trees, some of them are
[1:03:18] Speaker 3: quadrupedal in the trees. You take away those rainforests, the
[1:03:21] Speaker 3: ones that are upright in the trees are going to
[1:03:23] Speaker 3: be upright on the ground. They're going to be more
[1:03:25] Speaker 3: predisposed to be able to capitalize on their morphology that
[1:03:29] Speaker 3: already existed, to become more efficient at that bipedalism that
[1:03:34] Speaker 3: they can already do, but really poorly.
[1:03:36] Speaker 2: So when they first start walking upright, I say, first,
[1:03:39] Speaker 2: you know, and that the first series of the first
[1:03:41] Speaker 2: few thousand years or whatever, the feet are more awkward,
[1:03:45] Speaker 2: the pelvises aren't optimized, the spine etc. But the ones
[1:03:49] Speaker 2: who survive actually had, for lack of a better word,
[1:03:52] Speaker 2: they were born with a better model for the foot,
[1:03:55] Speaker 2: the pelvis, and the spine, and then they begin to reproduce.
[1:03:58] Speaker 2: Is that close.
[1:04:00] Speaker 3: Yeah, let's say, you know again, we're let's look at
[1:04:02] Speaker 3: our same population that we're just looking at. You know,
[1:04:04] Speaker 3: the trees start to disappear in our little upright ape
[1:04:07] Speaker 3: in the trees comes down to the ground. We got
[1:04:09] Speaker 3: a little family of them, let's say a population of
[1:04:11] Speaker 3: like ten And of those ten apes, they have to
[1:04:13] Speaker 3: come down from their few trees that are remaining to
[1:04:16] Speaker 3: move from tree patch to tree patch. Because we're living
[1:04:18] Speaker 3: in one tree patch, we eat all the fruit. We
[1:04:20] Speaker 3: need to move to the next one so that we
[1:04:21] Speaker 3: can survive. But the distance between our tree patch and
[1:04:23] Speaker 3: the next one is a mile, and on that mile
[1:04:26] Speaker 3: of open grassland, there's all sorts of big prehistoric predators
[1:04:31] Speaker 3: that are very happy to eat an ape that just
[1:04:34] Speaker 3: so happened to venture to the ground. Because no apes
[1:04:37] Speaker 3: are particularly quick on the ground, because we evolved in
[1:04:40] Speaker 3: the trees. We're great in the trees, but not on
[1:04:42] Speaker 3: the ground. So we have to move from point A
[1:04:44] Speaker 3: to point B in that family of ten individuals, some
[1:04:47] Speaker 3: are going to be slightly different than others with regard
[1:04:50] Speaker 3: to all sorts of different physical characterists, just like humans
[1:04:52] Speaker 3: are today, and the ones that are slightly better at
[1:04:55] Speaker 3: moving across that open, flat grassland. If a big group
[1:04:58] Speaker 3: of predators decides to attack our little family of ten,
[1:05:02] Speaker 3: the ones that they're going to get are going to
[1:05:03] Speaker 3: be the ones that are worse and moving bipedal lely,
[1:05:05] Speaker 3: even just for that brief distance. So you see an
[1:05:07] Speaker 3: enormous amount of natural selection right off the bat as
[1:05:11] Speaker 3: these guys are trying to get around on this new landscape, and.
[1:05:15] Speaker 2: Then the brains begin to get bigger. Is this like
[1:05:18] Speaker 2: the smarter ones we're also able to survive, So those
[1:05:21] Speaker 2: who had been I don't know. Is it random? Are
[1:05:23] Speaker 2: these characteristics If you have a family of ten and
[1:05:25] Speaker 2: some feet are better than others, it's just this, you know,
[1:05:28] Speaker 2: genes kind of moving around in a random way.
[1:05:31] Speaker 3: Yeah. So we're actually at a really interesting point in
[1:05:34] Speaker 3: time with these astrolobids, right because their brains are a
[1:05:36] Speaker 3: little bit bigger than chimps, but not by much. We
[1:05:38] Speaker 3: haven't seen a massive explosion in brain case size yet.
[1:05:42] Speaker 3: And what's weird about that is that, well, it was
[1:05:45] Speaker 3: weird to the people who discovered it because it's not intuitive.
[1:05:47] Speaker 3: You would expect that bipalism and big brains would evolve
[1:05:50] Speaker 3: at the same time, in tandem rising up to the
[1:05:53] Speaker 3: human level. But what we actually see is that those
[1:05:55] Speaker 3: trees disappear first. And you don't need a big brain
[1:05:57] Speaker 3: to be by pedal, you need to be bipedal to
[1:05:59] Speaker 3: be by peel. So what we see is that bipedalism
[1:06:02] Speaker 3: is evolving faster than those larger brains. Right, the brains
[1:06:05] Speaker 3: are getting a little bit bigger, but really not by much.
[1:06:08] Speaker 3: It didn't seem like smart's was super important at this
[1:06:11] Speaker 3: very early juncture. It seems like at first it was
[1:06:13] Speaker 3: just like can you get from point A to point B?
[1:06:16] Speaker 3: You No, evolution is selecting very quickly on what you
[1:06:18] Speaker 3: need to survive in that environment, not what would be
[1:06:20] Speaker 3: helpful you know what I mean. It's you know, to
[1:06:24] Speaker 3: use force terminology, it's like survival of the okayist. So
[1:06:28] Speaker 3: we're getting selection for these characters of walking upright, But
[1:06:32] Speaker 3: those big brains are lagging behind. They're just a little
[1:06:35] Speaker 3: bit bigger. A chimp, for example, is about three hundred
[1:06:37] Speaker 3: ccs or cubic centimeters, a human is twelve hundred right,
[1:06:41] Speaker 3: four times bigger, and then in between like in volume
[1:06:44] Speaker 3: I should say, in surface here and things like that,
[1:06:46] Speaker 3: and Oscolopithecus, these osceolopits are about five hundred and fifty,
[1:06:50] Speaker 3: so bigger than what we see in a chimp, really
[1:06:52] Speaker 3: almost double what you see in a chimp in the
[1:06:55] Speaker 3: smaller brainch chimps, but nowhere near humans, not even halfway
[1:06:59] Speaker 3: to humans yet.
[1:07:00] Speaker 2: All right, So as you say, I'm a gentle and
[1:07:02] Speaker 2: modern ape and I'm looking back seeing similarities in these
[1:07:06] Speaker 2: ancient fossils, etc. What's the next progression? What happens after
[1:07:11] Speaker 2: I become a biped out in the African savannah?
[1:07:14] Speaker 3: Yeah, so you know, by approximately three point three million
[1:07:18] Speaker 3: years ago, you're an upright ape, you're an ostelopath, but
[1:07:22] Speaker 3: you're still kind of a pinhead. I mean, you look
[1:07:24] Speaker 3: at these guys, and their brains are nothing to write
[1:07:26] Speaker 3: home about. Again, like that five hundred and fifty is
[1:07:28] Speaker 3: pushing it. That's what you see in the bigger males.
[1:07:30] Speaker 3: But now you're good. When you're on the savannah, you're upright,
[1:07:33] Speaker 3: and you're still maintaining some characteristics that are really primitive. Right,
[1:07:37] Speaker 3: you've still got really long arms, really curved fingers, and
[1:07:41] Speaker 3: really mobile shoulders, so that even though you're walking from
[1:07:44] Speaker 3: patch of trees to patch of trees to forage, you
[1:07:47] Speaker 3: don't have fire yet. And you're a big, slow ape
[1:07:51] Speaker 3: that lives on the ground. Where do you think you
[1:07:53] Speaker 3: want to sleep at night?
[1:07:55] Speaker 2: Probably a pie?
[1:07:56] Speaker 3: Probably a pie. So evolution is going to maintain those
[1:08:00] Speaker 3: characteristics that are going to keep you from getting eaten
[1:08:02] Speaker 3: when the sun sets. So these oscilopids still have characteristics
[1:08:05] Speaker 3: that they maintain from their ape ancestry, and we have
[1:08:08] Speaker 3: those today. We don't live in the trees, and yet
[1:08:11] Speaker 3: we still maintain these super flexible bodies that allow us
[1:08:15] Speaker 3: when we want to climb better than almost every mammal. Right,
[1:08:19] Speaker 3: we're not better than most primates, but we're better than
[1:08:21] Speaker 3: most mammals. So these osclopids are living on this landscape,
[1:08:25] Speaker 3: you know, three point three million years ago, they're still
[1:08:27] Speaker 3: spending quite a bit of time in the trees, namely
[1:08:29] Speaker 3: to forage and to sleep. At least, that's the logical
[1:08:34] Speaker 3: conclusion of this version of the savannah hypothesis that I'm
[1:08:37] Speaker 3: presenting to you. But they still need to be able
[1:08:39] Speaker 3: to move upright, and as they're living on this landscape,
[1:08:42] Speaker 3: moving from place to place, they start up to notice
[1:08:45] Speaker 3: that there are resources that they can exploit, but not
[1:08:49] Speaker 3: with their own bodies. Right, this is something that chimpanzees
[1:08:53] Speaker 3: can already do. So this isn't like, you know, shocking,
[1:08:55] Speaker 3: but it turns out that they're you know, the way
[1:08:57] Speaker 3: that trees work, that there are some trees that are
[1:09:00] Speaker 3: going to have fruits that have really hard exteriors, or
[1:09:02] Speaker 3: they produce nuts that have really hard exteriors, and it's
[1:09:04] Speaker 3: tough to get at the part inside that you want
[1:09:07] Speaker 3: to get at. Chimpanzees are smart enough to look at
[1:09:10] Speaker 3: that and say, well, I can't break it with my jaws,
[1:09:12] Speaker 3: but I bet if I take that big rock and
[1:09:14] Speaker 3: I smack it into this nut, it'll break. So they
[1:09:16] Speaker 3: do it. They smack it into the nut, and the
[1:09:18] Speaker 3: nut seeks into the ground and they're like, ah, there
[1:09:20] Speaker 3: needs to be a rock on the other side too.
[1:09:22] Speaker 3: So chimpanzees are capable of taking a nut and putting
[1:09:24] Speaker 3: it on top of a rock they're anvil, and then
[1:09:26] Speaker 3: taking a hammerstone and smashing the top and cracking the
[1:09:29] Speaker 3: nut to get the food inside. An Oscillopus were capable
[1:09:33] Speaker 3: of this too. In fact, remember their brains are a
[1:09:37] Speaker 3: little bit bigger than what we see with chimpanzees. So,
[1:09:40] Speaker 3: as it turns out, at three point three million years ago,
[1:09:43] Speaker 3: when we've got these oscilopis living on the landscape walking
[1:09:46] Speaker 3: by Peeley with a slightly bigger brain, we start to
[1:09:49] Speaker 3: find stone tools. At three point three million years ago,
[1:09:52] Speaker 3: at Lamechui, a pretty famous site, we find stone tools.
[1:09:56] Speaker 3: They're really really primitive, but they are more advanced than
[1:10:00] Speaker 3: what chimpanzees use today. So you might be thinking, what
[1:10:04] Speaker 3: are they using these tools for right three point three
[1:10:06] Speaker 3: million years ago, what could they possibly be using these
[1:10:08] Speaker 3: tools for? Well, maybe cracking open nuts, or maybe they'd
[1:10:12] Speaker 3: figured out that you can crack open more than just
[1:10:14] Speaker 3: nuts with a big rock. You can crack open bones.
[1:10:17] Speaker 3: And when you crack open bones, inside those bones there's
[1:10:21] Speaker 3: marrow that most animals on the savanna aren't going to
[1:10:23] Speaker 3: bother with hyena as well. But hyena isn't the predator
[1:10:26] Speaker 3: that kills everything. If a lion eats everything off of
[1:10:29] Speaker 3: a corpse and then leaves, there's a skeleton left behind,
[1:10:31] Speaker 3: and you as a hormin and are capable of chasing
[1:10:33] Speaker 3: off vultures walking up to it and picking up a bone,
[1:10:37] Speaker 3: and you now know you're smart enough to know that
[1:10:39] Speaker 3: there is marrow inside that bone, and maybe that happened.
[1:10:42] Speaker 3: You can see this logically right playing out. You've got
[1:10:45] Speaker 3: a hominin that's the oshinlopithec is walking along and they
[1:10:48] Speaker 3: see a bone and it's been traveled by wildebees. They
[1:10:50] Speaker 3: pick it up, and there's stuff in there that they
[1:10:52] Speaker 3: can eat, and then they put two and two together,
[1:10:54] Speaker 3: just as you know a chimp is capable of doing right,
[1:10:57] Speaker 3: and say, okay, well there's food in this. I can't
[1:11:00] Speaker 3: open this by myself. They see other complete, non broken
[1:11:02] Speaker 3: bones next to it. But if you slam it on
[1:11:04] Speaker 3: the ground, like in Sanley Kubrick's Space Odyssey, it'll break.
[1:11:08] Speaker 3: And if it's not brittle enough, if you're not strong
[1:11:10] Speaker 3: enough to break it yourself, you can take one of
[1:11:12] Speaker 3: those rocks that you've already been using to crack open
[1:11:14] Speaker 3: nuts and crack open this bone too and get it
[1:11:17] Speaker 3: the marrow inside. Now there's a really critical step that
[1:11:20] Speaker 3: is going on here, seth right, which is that bone
[1:11:23] Speaker 3: marrow is energetically a powerhouse. All organic material is which
[1:11:29] Speaker 3: is what are all animal material I guess I should say,
[1:11:31] Speaker 3: is which is why even herbivores across the animal kingdom
[1:11:34] Speaker 3: will opportunistically eat other animals if they can. Like you
[1:11:38] Speaker 3: can see a horse chop a little baby chicken. They'll
[1:11:41] Speaker 3: eat a chick, you know, if a chick wanders in
[1:11:43] Speaker 3: front of it. Chimpanzees don't eat a lot of meat,
[1:11:47] Speaker 3: but they do hunt actively meat. They hunt monkeys, they
[1:11:50] Speaker 3: hunt little antelopes that live in the rainforest. Females will
[1:11:54] Speaker 3: specifically sharpen sticks with their teeth and spear bush babies
[1:11:58] Speaker 3: in little cavities of trees that they can't reach with
[1:12:01] Speaker 3: their hands and eat that meat. Gorillas will opportunistically eat.
[1:12:05] Speaker 3: They won't hunt like chimpanzees do, but they'll opportunistically eat
[1:12:09] Speaker 3: eggs and little lizards and things like that. Same with orangutans,
[1:12:11] Speaker 3: same with gibbons. And what happens when you start doing
[1:12:15] Speaker 3: this consistently is you raise the amount of energy that
[1:12:21] Speaker 3: your body has available. You expand your energy pool. Now
[1:12:26] Speaker 3: the most expensive organ in your entire body. There's two
[1:12:30] Speaker 3: really expensive systems in your body. The first is your
[1:12:33] Speaker 3: gastrointestinal system because it's quite large, but the other one
[1:12:36] Speaker 3: is your brain. Your brain eats a lot, right. It
[1:12:39] Speaker 3: takes you know, anywhere from ten to twenty percent of
[1:12:42] Speaker 3: your daily intake calorically goes just to keeping your brain functioning.
[1:12:46] Speaker 3: So all organisms are limited by how big you know,
[1:12:49] Speaker 3: in how big they can grow their brain, by the
[1:12:51] Speaker 3: environment in which they live, by the food that they
[1:12:54] Speaker 3: have available to them. So, for instance, let's say you
[1:12:56] Speaker 3: have a horse, Right, horses eat like alfalfa and stuff
[1:12:59] Speaker 3: like that, and one day a horse is born with
[1:13:02] Speaker 3: a brain that's twenty percent bigger than the average horse's brain.
[1:13:06] Speaker 3: If it's living in the wild, that horse is probably
[1:13:08] Speaker 3: not going to experience a selection for that big brain.
[1:13:11] Speaker 3: It's probably going to die young. Because that brain is
[1:13:13] Speaker 3: super expensive, and horses eat alfalfa and grass, it can't
[1:13:16] Speaker 3: fuel that big brain. You have to have a diet
[1:13:18] Speaker 3: that's able to support a big brain, which is why
[1:13:21] Speaker 3: virtually every animal that has a big brain, with a
[1:13:24] Speaker 3: few exceptions, tends to incorporate some amount of animal product
[1:13:29] Speaker 3: into their diets. So what happens when you have an
[1:13:32] Speaker 3: ostralopith living on a landscape that's just figured out how
[1:13:34] Speaker 3: to explode the metabolic budget that they have available to them. Well,
[1:13:39] Speaker 3: now the individuals that are born with slightly larger brains
[1:13:42] Speaker 3: can fuel them. Their brains are actually able to provide
[1:13:46] Speaker 3: a benefit to them in their environment because they're now
[1:13:48] Speaker 3: exploiting more calorically dense resources. So, now when you're born
[1:13:52] Speaker 3: with a bigger brain, you can innovate, right, you can
[1:13:55] Speaker 3: innovate with better tools to procure even more animal resources,
[1:13:59] Speaker 3: which means you can grow and even bigger brain, which
[1:14:01] Speaker 3: means you can innovate, which means that you can procure
[1:14:03] Speaker 3: even more animal resources, which means you can get an
[1:14:05] Speaker 3: even bigger brain, which means that you can innovate even
[1:14:08] Speaker 3: more and procure even more animal resources. When tools enter
[1:14:11] Speaker 3: the scene and start to open up this dietary niche
[1:14:15] Speaker 3: for dominance, that's when you see the brain case size explode.
[1:14:20] Speaker 2: I want to come back to braincase size. Tools. And
[1:14:23] Speaker 2: you say tools, I mean the creationist might argue, well,
[1:14:26] Speaker 2: was a randomly shaped rock that looked like a what
[1:14:30] Speaker 2: I mean, what do you mean by tool? So many
[1:14:32] Speaker 2: million years ago?
[1:14:34] Speaker 3: Yeah, So a tool is a rock that's been intentionally shaped.
[1:14:37] Speaker 3: And when I say intentionally shaped, I mean they exhibit
[1:14:39] Speaker 3: percussive fracture patterns that can only be formed if you
[1:14:43] Speaker 3: have something that is picking them up and smashing them
[1:14:46] Speaker 3: together over and over and over again in specific ways.
[1:14:50] Speaker 3: A rock rolling down a hill cannot form those percussive patterns.
[1:14:54] Speaker 3: It's very specific to the type of percussive action that
[1:14:59] Speaker 3: require is basically something picking them up and saying, Okay,
[1:15:02] Speaker 3: I'm going to do this over and over and over
[1:15:04] Speaker 3: and over and over again.
[1:15:05] Speaker 2: So because this is not a natural phenomen I mean,
[1:15:08] Speaker 2: we can infer intentionality. This was purposefully done.
[1:15:12] Speaker 3: Yeah, I mean purposefully done. It was done. I would
[1:15:14] Speaker 3: prefer the word intentionally because purposefully sort of implies that they're,
[1:15:18] Speaker 3: you know, saying, oh, I'm going to do this for
[1:15:20] Speaker 3: this purpose, which maybe they were. But we also see
[1:15:22] Speaker 3: baby chimpanzees today. They pick up a rock and they
[1:15:26] Speaker 3: intentionally smack it on the ground a bunch of times.
[1:15:28] Speaker 3: Maybe they're not doing it for a purpose or doing
[1:15:30] Speaker 3: it because it's fun, right, I mean, that's that's how
[1:15:32] Speaker 3: this starts, though, is that you've got an individual that
[1:15:35] Speaker 3: tries something, you know, just because why not. They realize
[1:15:38] Speaker 3: that there's there is an advantage to doing that, and
[1:15:42] Speaker 3: that's how tools enter into the culture of a given
[1:15:47] Speaker 3: social animals population. Right, Chimpanzees today use all sorts of
[1:15:52] Speaker 3: different tools. Right. They don't just use rocks. They use
[1:15:55] Speaker 3: all sorts of different sticks and leaves and vegetation and
[1:15:59] Speaker 3: you know, pieces of grass to do all sorts of
[1:16:01] Speaker 3: different jobs within the environments in which they live. And
[1:16:04] Speaker 3: the types of toolboxes that chimpanzees use differ depending on
[1:16:08] Speaker 3: the population of chimpanzees that you're looking at, because they've
[1:16:11] Speaker 3: developed many of them independently. So the same would be
[1:16:15] Speaker 3: true for oscilopuds. And what's fascinating is that we know
[1:16:19] Speaker 3: that chimpanzees use tools today, we see them using tools, right.
[1:16:22] Speaker 3: This is this is common knowledge and easy to see,
[1:16:25] Speaker 3: although it was groundbreaking when when Jane Goodall you know,
[1:16:28] Speaker 3: published on it in the in the nineteen hundreds, right,
[1:16:31] Speaker 3: it was new then nineteen sixties, I believe. But what
[1:16:35] Speaker 3: that means is that because we see the patterns that
[1:16:37] Speaker 3: rocks form when we intentionally make them, or when a
[1:16:39] Speaker 3: chimpanzee smashes a rock onto another rock, you can actually
[1:16:42] Speaker 3: go back in time and see the archaeological history of
[1:16:45] Speaker 3: chimpanzees at sites that they live at today. You can
[1:16:48] Speaker 3: go back a thousand years dig down into the into
[1:16:50] Speaker 3: the soil, you can pull up rocks that that same
[1:16:53] Speaker 3: population of chimpanzees, you know, tens of generations earlier used
[1:16:56] Speaker 3: to make tools. Then, right, used tools, I should say, then,
[1:17:01] Speaker 3: so it's the same principle. We know what fracture patterns
[1:17:04] Speaker 3: form stone tools today. So when we find them in
[1:17:06] Speaker 3: the past, and we know that nature can't produce these
[1:17:09] Speaker 3: types of stone of stone fractures, right, we know that
[1:17:13] Speaker 3: they were made by someone, not just something.
[1:17:17] Speaker 2: So here we are we're optimizing, we are well, let's say,
[1:17:21] Speaker 2: natural selection is optimizing us to be bipedal. Our brains
[1:17:26] Speaker 2: are growing, our diets are supporting that. I guess are
[1:17:30] Speaker 2: we already covered in hair or were we always covered
[1:17:32] Speaker 2: in hair? And when does that begin to change? And
[1:17:35] Speaker 2: does any of this relate to the next skull? I'm
[1:17:37] Speaker 2: fascinated by your skull collection, Erica. What's the next step?
[1:17:40] Speaker 2: What happens?
[1:17:42] Speaker 1: Yeah?
[1:17:42] Speaker 3: I mean, so you've got you know, three point three
[1:17:44] Speaker 3: million years ago, we've got the Limequis stone tool culture,
[1:17:46] Speaker 3: and very very quickly that stone tool culture is going
[1:17:49] Speaker 3: to explode in tandem with brain case size. Right, So,
[1:17:53] Speaker 3: hominins that live shortly, you know, some of them are
[1:17:55] Speaker 3: contemporaneous with some of them are very shortly after. Genus
[1:17:59] Speaker 3: Homo is going to come on the scene, roughly two
[1:18:01] Speaker 3: point eight million years ago, so about half a million
[1:18:03] Speaker 3: years after all schili pits first start using tools. And
[1:18:06] Speaker 3: I know there are gonna be pedants out there. It
[1:18:07] Speaker 3: might be kennyanthropists, but they're very similar. So we'll put
[1:18:10] Speaker 3: a pin in that Genus home is gonna come along
[1:18:13] Speaker 3: and Homo is going to be discovered first by you know,
[1:18:16] Speaker 3: the leaky's again at old of I Gorge, and they
[1:18:19] Speaker 3: discovered stone tools there first, but they discovered them there
[1:18:21] Speaker 3: with a much more primitive hominin known as paranthropists. They
[1:18:24] Speaker 3: call them Zingi anthropists at the time. I mentioned this
[1:18:26] Speaker 3: in our last talk. But you know, you've got this this,
[1:18:29] Speaker 3: this stone tool and this really primitive looking hominin, and
[1:18:31] Speaker 3: then they discover Homo, right, they discover Homo habilists to
[1:18:35] Speaker 3: be precise. Then you know, you got one skull that's
[1:18:37] Speaker 3: bigger brained and looks more like a human, and then
[1:18:39] Speaker 3: you have a smaller brained one that looks much more
[1:18:42] Speaker 3: you know, apish, and they're like, okay, Genus Homo probably
[1:18:44] Speaker 3: made the tools at old of I Gorge, and these
[1:18:46] Speaker 3: stone tools are different from the ones at Lamechway. They're
[1:18:50] Speaker 3: more advanced. These stone tools have been they're starting to
[1:18:53] Speaker 3: be shaped a little bit. They're old ones stone tools
[1:18:55] Speaker 3: and nothing to write home about, but they're certainly more
[1:18:57] Speaker 3: advanced than the ones who you saw at Lamechway. When
[1:19:00] Speaker 3: you look at Homo Habilis's brain, it's bigger too. Now
[1:19:03] Speaker 3: the lower end of Homohabilist's brain dips and I'm going
[1:19:06] Speaker 3: to give you a chart here, Seth to put up
[1:19:08] Speaker 3: so you can see what's overlapping with what. But the
[1:19:10] Speaker 3: lower end of Homo Habilist's brain case range is dipping
[1:19:13] Speaker 3: into the higher end of Allstchilopithecus. But it's like a
[1:19:15] Speaker 3: it's like a little than diagram right where they overlap
[1:19:18] Speaker 3: is small but present. But Homo habilists is starting to
[1:19:20] Speaker 3: push the boundary. The brains are getting bigger and the
[1:19:22] Speaker 3: tools are getting more advanced. Right, Homo habilist is going
[1:19:26] Speaker 3: to dominate the landscape for a little bit and then
[1:19:28] Speaker 3: after it maybe contemporaneous with it, like the relationships are
[1:19:31] Speaker 3: kind of unclear, But you have an even bigger brained,
[1:19:34] Speaker 3: older member of genus Homo homobrid offenses. So, to put
[1:19:37] Speaker 3: this into perspective, Ostelopithecus's brain is only getting up to
[1:19:40] Speaker 3: five hundred and fifty ccs max. Homo habilist's brain can
[1:19:44] Speaker 3: can push. It can get quite a bit bigger at
[1:19:46] Speaker 3: like roughly seven hundred and twenty ce seeds right, give
[1:19:49] Speaker 3: or take. And then homovered Offensis comes along. It's younger
[1:19:53] Speaker 3: than Habylis and its brain reaches into the eight hundred ccs.
[1:19:56] Speaker 3: So we're starting to see this ramping up of brain
[1:19:58] Speaker 3: case size along with the ramping up of stone tool use. Now,
[1:20:02] Speaker 3: as far as are these guys covered with hair, we're
[1:20:04] Speaker 3: not really sure. Right, hair can fossilize, but not not
[1:20:07] Speaker 3: well there's we definitely know when the hair has disappeared, though,
[1:20:13] Speaker 3: And when the hair has disappeared is when we reach
[1:20:15] Speaker 3: the hominin that follows homoword offenses, who lived about two
[1:20:17] Speaker 3: million years ago, and around that same time we see
[1:20:20] Speaker 3: the emergence of Homo erectus. Homo Erectus was first discovered
[1:20:23] Speaker 3: in Asia. But homo erectus is fascinating because again, like
[1:20:28] Speaker 3: I said, they discovered in Asia first, and they're like
[1:20:31] Speaker 3: humans evolved in Asia. But shortly after it was discovered
[1:20:34] Speaker 3: in Asia, they start to find every more primitive, every
[1:20:37] Speaker 3: single one of the more primitive hominids in Africa, which
[1:20:40] Speaker 3: means that at some point humans you know, had evolved
[1:20:43] Speaker 3: to a point in africo where they left. Now, there's
[1:20:45] Speaker 3: something that's really difficult about leaving Africa, and that's that
[1:20:49] Speaker 3: you have to go through a lot of desert to
[1:20:51] Speaker 3: get out of there, which means that you know, it
[1:20:53] Speaker 3: means a couple of things. One, you have to be
[1:20:55] Speaker 3: really really really good at not overheating something that fur
[1:20:58] Speaker 3: is going to make very difficult. Two, you need to
[1:21:01] Speaker 3: be able to carry your water with you, because if
[1:21:03] Speaker 3: you're crossing a big desert, you know, you're basically going
[1:21:06] Speaker 3: to dehydrate to death if you don't have a means
[1:21:09] Speaker 3: of carrying your water. And three, you need to be
[1:21:13] Speaker 3: really pretty intelligence you can plot your route through the
[1:21:16] Speaker 3: desert to leave Africa. Now, the fact that we have
[1:21:18] Speaker 3: Homo erectus outside of Africa by almost two million years,
[1:21:23] Speaker 3: by one point nine to five, means that Homo erectus
[1:21:27] Speaker 3: like existed and had a brain that was large enough
[1:21:30] Speaker 3: to start to plot this kind of thing out, certainly
[1:21:33] Speaker 3: by two million years ago. It's living at the same
[1:21:35] Speaker 3: time as some of the earlier members of genus Homo,
[1:21:37] Speaker 3: and even ostralopps are still around because something doesn't go
[1:21:41] Speaker 3: extinct just because it leaves a more successful quote unquote descendant.
[1:21:46] Speaker 3: You know, wolves are the ancestors of dogs, but we
[1:21:49] Speaker 3: have dogs and wolves today still in the same way.
[1:21:51] Speaker 3: Genus Homo descends from Australopithecus, but they still live at
[1:21:54] Speaker 3: the same time for a really long time during the
[1:21:56] Speaker 3: fossil record. So you know, what was it about Homo
[1:21:59] Speaker 3: erectus what made it so good at getting out of Africa? Well,
[1:22:04] Speaker 3: when we look at the morphology of this thing, it
[1:22:09] Speaker 3: becomes pretty obvious. Right the brain there's a huge difference
[1:22:13] Speaker 3: in the braincase size of Australopithecus and Homo erectus. You know,
[1:22:17] Speaker 3: I've got these two right here, and it serves to
[1:22:20] Speaker 3: it serves that was true here and I should probably
[1:22:24] Speaker 3: show you as well. Here's Homo habilis smaller than Homo erectus,
[1:22:28] Speaker 3: but you know, bigger than Australopithecus. And then we have
[1:22:33] Speaker 3: rutal fens. I'll make this better, jeez. And then we
[1:22:38] Speaker 3: have rutal Fensis which is even closer, even closer to
[1:22:43] Speaker 3: homo erectus, and then we reach homo erectus right, So
[1:22:46] Speaker 3: those brain case sizes are getting bigger and bigger and bigger,
[1:22:49] Speaker 3: and by the time you reach this guy, the first
[1:22:50] Speaker 3: hominin to leave Africa, brains are big. And because we
[1:22:54] Speaker 3: also find homo erectus in very cold places, it serves
[1:22:57] Speaker 3: to reason that these guys were also wearing clothes. How
[1:23:02] Speaker 3: can we tell that they were wearing clothes just because
[1:23:04] Speaker 3: we find them in cold places. How do we know
[1:23:06] Speaker 3: that they didn't just still have hair when they went
[1:23:08] Speaker 3: to these cold places, you know, and they figured out
[1:23:10] Speaker 3: how to throw more regulate when they were in the desert. Well,
[1:23:13] Speaker 3: when you run a phylogeny, so a family tree at
[1:23:16] Speaker 3: the species level, on the difference between human head lice
[1:23:20] Speaker 3: and body lice and pubic lice, which you find is
[1:23:23] Speaker 3: that they split right around the time that homo erectus
[1:23:27] Speaker 3: like leaves Africa, which suggests that they weren't able to
[1:23:31] Speaker 3: live on our body hair anymore because we didn't have it.
[1:23:34] Speaker 3: They were isolated to our heads, the tops of our
[1:23:36] Speaker 3: heads in our pubic region where we still had hair.
[1:23:39] Speaker 3: And that's because the hair was gone and the clothes
[1:23:41] Speaker 3: arrived so that we could live in these cold, cold regions.
[1:23:45] Speaker 2: So what are we talking about? Are you talking about
[1:23:46] Speaker 2: animal skins? When you say clothing? Of course, you know
[1:23:49] Speaker 2: some people are thinking about Gucci and Louis Biton. What
[1:23:52] Speaker 2: are we talking about here?
[1:23:53] Speaker 3: Yeah, I mean I think we are talking about animal skins. Right,
[1:23:56] Speaker 3: They're not weaving anything yet, so it you know, we
[1:24:00] Speaker 3: you suggest that they're probably taking the skins off of
[1:24:02] Speaker 3: the animals that they're hunting. And hunting is argued to
[1:24:06] Speaker 3: be one of the big innovations of Homo erectus, in
[1:24:09] Speaker 3: part because their brain size is of course exploding, but
[1:24:12] Speaker 3: also because their their bodies have changed. You know, we've
[1:24:15] Speaker 3: got bipedalism on the scene. By the time Astrolopithecus is there,
[1:24:18] Speaker 3: those guys are walking up right every time they come
[1:24:20] Speaker 3: to the ground. But when you look at home, more erectus,
[1:24:22] Speaker 3: and we've got this wonderful skeleton culture. Connaboy that I've
[1:24:24] Speaker 3: had the pleasure of, you know, seeing and touching myself
[1:24:28] Speaker 3: out of Kenya, that this thing has the proportions of virtually,
[1:24:32] Speaker 3: you know, virtually identical to a modern human. I mean,
[1:24:34] Speaker 3: it's called long legs, shorter arms. Right, Its body is
[1:24:37] Speaker 3: built for long distances, which is perfect for a hominin
[1:24:41] Speaker 3: that wants to leave Africa, and it's also perfect for
[1:24:44] Speaker 3: the type of hunting that humans are really, really good at,
[1:24:46] Speaker 3: to the exclusion of almost every other animal on the planet.
[1:24:49] Speaker 3: We're persistence hunters, so we're not fast seth right like
[1:24:52] Speaker 3: you and me. We could be the best runners in
[1:24:54] Speaker 3: the world. You say, bolt right, could try to run
[1:24:56] Speaker 3: down a gazelle, He's not going to catch it. In fact,
[1:24:58] Speaker 3: you say, both is going to be out run by
[1:25:00] Speaker 3: a house cat. So how do we get How did
[1:25:02] Speaker 3: we hunt? And the answer is that the earliest humans
[1:25:06] Speaker 3: were built for not speed, but endurance where we don't
[1:25:10] Speaker 3: have hair anymore right at the time that Homo erectus
[1:25:13] Speaker 3: is here, which means that you know, we're basically baking
[1:25:17] Speaker 3: in the sun. We need to be able to cool
[1:25:19] Speaker 3: ourselves off, and that's select the pressure led to the
[1:25:22] Speaker 3: development of more sweat glands or acron glands. We have
[1:25:25] Speaker 3: three times the amount of sweat glands compared to a chimpanzee.
[1:25:28] Speaker 3: So the persistence hunting hypothesis argues that we were basically
[1:25:32] Speaker 3: honed for living and thermoregulating to be you know, under
[1:25:36] Speaker 3: the hot sun on the savannah. But those same adaptations
[1:25:38] Speaker 3: allowed us to cool off better than any other animal
[1:25:41] Speaker 3: that that's out there, pretty much because because we can
[1:25:43] Speaker 3: sweat and cool our bodies, which means that we could
[1:25:46] Speaker 3: see a gazelle and start to chase it, and the
[1:25:49] Speaker 3: gazelle will, you know, immediately run past out of our range.
[1:25:52] Speaker 3: It's running fast, it's running quickly, and eventually we can't
[1:25:55] Speaker 3: see it anymore. But we're intelligent. Our brains have already
[1:25:57] Speaker 3: gotten big. And this is two million years ago. We're
[1:25:59] Speaker 3: talking really one point six when we're looking at Nuria
[1:26:03] Speaker 3: Kotomi boy, the Charcono boy that I just mentioned, one
[1:26:05] Speaker 3: six one point seven. So you know, the gazell's out
[1:26:08] Speaker 3: of sight, but your brain is big, right, you're able
[1:26:10] Speaker 3: to track it. You know, we're not using our sense
[1:26:12] Speaker 3: of smell, we're using our eyes or following these little clues.
[1:26:15] Speaker 3: And people hunt like this today still they're they're persistence
[1:26:19] Speaker 3: hunters in South Africa that still hunt like this. So
[1:26:21] Speaker 3: you follow the gazelle. You can't see it, but you
[1:26:23] Speaker 3: follow the tracks that it makes in the dirt. You
[1:26:25] Speaker 3: follow the way that it's broken vegetation, and you come
[1:26:28] Speaker 3: upon it again, and the gazelle sees you and it
[1:26:30] Speaker 3: runs again. It's like, how did this thing catch up
[1:26:32] Speaker 3: to me? But you're still following, right, it's running, you're
[1:26:35] Speaker 3: following it, and you don't stop. Right. This thing keeps
[1:26:38] Speaker 3: trying to stop and cool off, but you don't have
[1:26:40] Speaker 3: to because you're sweating the whole time and your home
[1:26:42] Speaker 3: will erect this. So you're probably carrying your water with you.
[1:26:45] Speaker 3: You already eat a lot of meat. You know that
[1:26:48] Speaker 3: organs can hold water. We use water skins for you know, millennia.
[1:26:52] Speaker 3: You're probably carrying your water along with you as you go,
[1:26:55] Speaker 3: or you know where the spots to get water are.
[1:26:58] Speaker 3: So you're following this gazelle and this dance continues for hours.
[1:27:01] Speaker 3: Where it stops, you catch up again, it runs, it stops,
[1:27:05] Speaker 3: you catch up again, and so on and so forth,
[1:27:07] Speaker 3: until eventually the sun has baked this thing. It hasn't
[1:27:10] Speaker 3: been able to stop for water, it hasn't been able
[1:27:12] Speaker 3: to cool its body down. Meanwhile, you haven't even overheated,
[1:27:15] Speaker 3: and you're carrying a big sharp stick. So eventually you
[1:27:18] Speaker 3: come up on it and it's laying exhausted and all
[1:27:21] Speaker 3: you have to do is make to throw and you've
[1:27:24] Speaker 3: gotten meat for the entire tribe again, right, So you're
[1:27:27] Speaker 3: built for persistence hunting. You're capable of doing it. This
[1:27:30] Speaker 3: is something that works. Like I said, we see people
[1:27:32] Speaker 3: doing it today. And so now you're fueling that feedback
[1:27:36] Speaker 3: loop with the big brain to grow it even larger
[1:27:40] Speaker 3: and innovate even more. All the while, you're starting to
[1:27:42] Speaker 3: get curious as to what's north past that big, impenetrable desert,
[1:27:46] Speaker 3: and you're thinking to yourself, you know, I can carry
[1:27:49] Speaker 3: my water when I'm hunting this gazelle. Why don't we
[1:27:53] Speaker 3: just go and we'll carry our water with us, We'll
[1:27:55] Speaker 3: drag our food with us. And that's what ends up happening.
[1:27:58] Speaker 3: Homeorectus penetrates through the desert, you know, the Sahara, and
[1:28:01] Speaker 3: up north through the Levant, and they break into Europe
[1:28:05] Speaker 3: and they break into to East Asia and they look very,
[1:28:08] Speaker 3: very similar to us. But at the same time, and
[1:28:11] Speaker 3: when you look at the skull of this thing, you
[1:28:13] Speaker 3: can recognize it as human. But the brow reach is
[1:28:16] Speaker 3: so chimp like, the teeth are enormous, it's prognatic. The
[1:28:19] Speaker 3: brain case is big, but it's still not as big
[1:28:21] Speaker 3: as ours. Right, this thing is, this thing would have
[1:28:24] Speaker 3: looked really really avish in a lot of different ways.
[1:28:28] Speaker 3: And the body hair is disappearing, but it's probably not
[1:28:30] Speaker 3: completely gone. So you know, you got this kind of
[1:28:33] Speaker 3: shaggy looking human, you know, with these big, you know,
[1:28:36] Speaker 3: British features that's brilliant penetrating out into the rest of
[1:28:40] Speaker 3: the world and everywhere, these populations of homo Erectus stop,
[1:28:44] Speaker 3: you know, and they settle, and then another group, being
[1:28:47] Speaker 3: the curious apes that we are, decide to strike out again.
[1:28:51] Speaker 3: So it's leaving these little populations of itself everywhere it goes,
[1:28:54] Speaker 3: and those populations are now subject to completely different pressures
[1:28:58] Speaker 3: than you know, the homo erectus that was back in Africa, right,
[1:29:02] Speaker 3: you get Neanderthals evolve in Europe. These big, like robust,
[1:29:07] Speaker 3: you know, cold adapted is the argument that's made hominins
[1:29:10] Speaker 3: that are ideal for living in these could or conditions.
[1:29:12] Speaker 3: They've got a big nose to warm up the air.
[1:29:14] Speaker 3: They've got big robust bodies for you know, short sprinting
[1:29:17] Speaker 3: over rocky terrain. You've got another group of homo Erectus
[1:29:20] Speaker 3: that settles out in East Asia, that's going to eventually
[1:29:23] Speaker 3: beget denisovans, another really mysterious, enigmatic group of hominins that lives,
[1:29:28] Speaker 3: you know, in these kind of crazy conditions. Homo Erectus
[1:29:31] Speaker 3: is going to persist there. The argument goes that home
[1:29:33] Speaker 3: Erectus is also the ancestor of Homo floresiensis those little
[1:29:36] Speaker 3: three foot tall hobbit hominins that you are on the
[1:29:40] Speaker 3: island of florests that you can only get to if
[1:29:42] Speaker 3: you've got like you get washed there by a storm
[1:29:44] Speaker 3: or if you you know, row there, you get like
[1:29:47] Speaker 3: on a log and you push yourself there. The Homo
[1:29:49] Speaker 3: Erectus is enormously innovative, and it's the parent population, the
[1:29:53] Speaker 3: parent species of all of these different hominins that evolve
[1:29:56] Speaker 3: outside of Africa. All the while, there's another group of
[1:29:59] Speaker 3: Homo Erectus bill in Africa that is continuing to change
[1:30:03] Speaker 3: in this harsh, harsh environment there, and it's going to
[1:30:06] Speaker 3: stay lanky, and it's going to stay you know, long
[1:30:09] Speaker 3: and lean, and that's going to be the population of
[1:30:13] Speaker 3: Homo erectus that's eventually going to lead to Homo sapiens.
[1:30:17] Speaker 3: And what's insane is that all of these populations are
[1:30:19] Speaker 3: developing technologies, right, they're starting to figure out they know
[1:30:23] Speaker 3: how to use fire at this point in time, they're
[1:30:26] Speaker 3: carrying their water around. Like I said, they're starting to
[1:30:28] Speaker 3: figure out, you know, more advanced weapons. They're using the
[1:30:30] Speaker 3: Ashulian tool industry, which is this beautiful type of tool
[1:30:33] Speaker 3: that's snapped and it pierces the skin of animals extremely well.
[1:30:37] Speaker 3: They're able to collect ocean resources like molluscs and fish, right,
[1:30:42] Speaker 3: and we find these in their camps, the bones of
[1:30:44] Speaker 3: fish cooked you know, in boats of the teeth var
[1:30:47] Speaker 3: angeal teeth of fish cooked in Homo erectus fireplaces and hearts,
[1:30:52] Speaker 3: and this is happening everywhere. Hominin's are unstoppable. This this
[1:30:55] Speaker 3: big brain meat feedback loop has just you know, launched
[1:30:59] Speaker 3: them into the strata. And their bodies are perfectly built
[1:31:01] Speaker 3: for travel. I mean, it's the perfect storm that only
[1:31:05] Speaker 3: emerged because you got this curious Australopithecus that decides to
[1:31:08] Speaker 3: smash a bone open.
[1:31:10] Speaker 2: As we've come from seven million years ago and edge
[1:31:13] Speaker 2: much much closer to the modern day, I'm going to
[1:31:16] Speaker 2: talk about social groups, tribalism, and the attributes that we
[1:31:20] Speaker 2: have in the human body. That reveal our primate origins.
[1:31:24] Speaker 2: That and more. Next, continuing my conversation today with an
[1:31:34] Speaker 2: expert on how humans evolved. She is host of the
[1:31:38] Speaker 2: Gutsig given channel Erica and taking us on the journey
[1:31:42] Speaker 2: from our quote unquote lowly origins to the modern day.
[1:31:48] Speaker 2: I don't want to digress too much, but we also
[1:31:52] Speaker 2: see as a survival mechanism more than just the body
[1:31:55] Speaker 2: characteristics behaviors, specifically in regard to social groups, right. I mean,
[1:31:59] Speaker 2: those who are going and alone on the African savannah
[1:32:02] Speaker 2: are probably more easy meat, where those who coalesced and
[1:32:06] Speaker 2: created tribes, and we talk a lot about modern day
[1:32:09] Speaker 2: tribalism and these sort of they're leftovers from our evolutionary past.
[1:32:14] Speaker 2: But that'd be a fair way to say it. I
[1:32:15] Speaker 2: mean we are tribal primates, oh for sure.
[1:32:19] Speaker 3: And I mean this is something that's far older than
[1:32:22] Speaker 3: Homo erectus. I mean we see this in chimps. Chimpanzees
[1:32:24] Speaker 3: today live in groups that will systematically patrol their territory
[1:32:29] Speaker 3: and if they encounter loan members outside of the group,
[1:32:31] Speaker 3: they'll kill him, you know, and they don't just kill
[1:32:33] Speaker 3: him in a simple way. They tear him to pieces.
[1:32:36] Speaker 3: They gouge out his eyes, they rip off his testicles.
[1:32:38] Speaker 3: I mean, they're really ruthless. And these chimpanzees, if they
[1:32:42] Speaker 3: find out that there's an entire population living in an
[1:32:45] Speaker 3: adjacent society or in an adjacent territory, they'll get the
[1:32:48] Speaker 3: gang together. They'll go into that adjacent territory and wipe
[1:32:53] Speaker 3: out the adjacent population. I mean it's they do it
[1:32:57] Speaker 3: on purpose, and they specifically will will not wipe out females, right,
[1:33:01] Speaker 3: They'll try to incorporate the females into their group, but
[1:33:03] Speaker 3: the males our toast.
[1:33:05] Speaker 2: So before the move up into Europe, I mean, we're
[1:33:07] Speaker 2: talking about early primates. Evidence of early primates acting in
[1:33:11] Speaker 2: social groups for survival and to thrive well into what
[1:33:15] Speaker 2: millions of years ago?
[1:33:16] Speaker 3: Yeah, I mean seven million years ago the common ancestor
[1:33:19] Speaker 3: of humans and chimps, And we see this behavior in
[1:33:21] Speaker 3: humans and chimps. Right, that the tribalism exists in humans
[1:33:24] Speaker 3: and chimpanzees and bonobos, which suggests that since it's in
[1:33:28] Speaker 3: both of us now, it's much more reasonable to propose
[1:33:31] Speaker 3: that it emerged in our common ancestor we retained it,
[1:33:34] Speaker 3: as compared to saying we both independently evolved it, which
[1:33:38] Speaker 3: meant that every single hominin group that we've been talking
[1:33:40] Speaker 3: about along the way is a social, tribal, vengeful, compassionate
[1:33:46] Speaker 3: animal that is capable of immense cruelty and also immense kindness.
[1:33:53] Speaker 3: I mean, we see in these early hominins that leave
[1:33:56] Speaker 3: in Homo erectus, you know, the first hominin that leaves Africa.
[1:34:00] Speaker 3: Forrest talks about this example of the time, but it
[1:34:02] Speaker 3: bears repeating. We have a cranium a skull from one
[1:34:06] Speaker 3: of these guys, and it's a gummer, right, So it's
[1:34:09] Speaker 3: lost all its teeth to and it lost all its
[1:34:11] Speaker 3: teeth pretty early, and then the mandible fused around where
[1:34:14] Speaker 3: the sockets for the teeth used to be. If you
[1:34:17] Speaker 3: don't have any teeth, you can't eat. If you can't
[1:34:19] Speaker 3: chew your own food, you die, right. So what that
[1:34:21] Speaker 3: means is that this guy lost all his teeth and
[1:34:24] Speaker 3: survived for years cared for by other members of his group.
[1:34:28] Speaker 3: There's no other way he could have survived, right. He
[1:34:30] Speaker 3: relied on his group to choose food for him and
[1:34:34] Speaker 3: keep him going. Right, we're talking about a hominin, you know,
[1:34:36] Speaker 3: we're talking about talking about this guy, right, this guy's
[1:34:40] Speaker 3: caring for its sick. This guy's making sure that the
[1:34:43] Speaker 3: members of it, of his group that are you know,
[1:34:45] Speaker 3: infirm or otherwise you know, differently abled or managing to
[1:34:50] Speaker 3: live as long as anybody else because they love them. Right.
[1:34:55] Speaker 3: At the same time, we find evidence on some of
[1:34:57] Speaker 3: these hominins, you know, there's arguments made for Neanderthal remains
[1:35:02] Speaker 3: out of I think it's out of Sema Sima de Laswasos,
[1:35:04] Speaker 3: the site that have specific head trauma wounds that show
[1:35:08] Speaker 3: they we're murdered, right, I mean, these guys are they're
[1:35:12] Speaker 3: us and in a way chimpanzees are us too, I mean,
[1:35:16] Speaker 3: or we're them, or these characteristics are older than both
[1:35:19] Speaker 3: of us, which is my opinion personally. They're just amplifying.
[1:35:22] Speaker 2: Humans, just classic in grouping and out grouping. And I
[1:35:26] Speaker 2: don't mean to uh, I don't mean to say that
[1:35:29] Speaker 2: social in grouping is indigenous or exclusive to primates, but
[1:35:32] Speaker 2: I mean, now most interested in primates. And then of
[1:35:36] Speaker 2: course that brings me to the next evolution in our
[1:35:40] Speaker 2: journey toward modern day, toward the homeless sapient. I guess
[1:35:45] Speaker 2: what happens next, Erica, Yeah, I.
[1:35:47] Speaker 3: Mean, so you've got this guy right, that Neanderthals, and
[1:35:52] Speaker 3: these guys are these guys are really phenomenal. They look
[1:35:54] Speaker 3: really similar to Erectus in a lot of ways, but
[1:35:57] Speaker 3: in other ways they're they're pretty different. They're different than
[1:35:59] Speaker 3: the tea. Their brains are a lot bigger. Neanderthals. Actually,
[1:36:03] Speaker 3: their brains got larger than ours did. They got even
[1:36:06] Speaker 3: bigger brands than us, which is kind of crazy to
[1:36:08] Speaker 3: think about, and it tells us a lot about how
[1:36:11] Speaker 3: it's not necessarily the size of the brain that matters,
[1:36:13] Speaker 3: but how it's organized. Because we're here and they're not.
[1:36:16] Speaker 3: So clearly we were doing something right.
[1:36:18] Speaker 2: Giving a timeframe real fast when you say Neanderthals, to
[1:36:21] Speaker 2: place that in the timeline.
[1:36:23] Speaker 3: For us, yeah, of course. So Homo erectus leaves Africa
[1:36:26] Speaker 3: two million years ago, and it establishes these populations all
[1:36:29] Speaker 3: over the world, the old world, I should say. It's
[1:36:31] Speaker 3: not made it over seas to you know, North and
[1:36:34] Speaker 3: South America, but it's dropping populations in Europe that are
[1:36:37] Speaker 3: going to evolve into Neanderthals around eight hundred thousand to
[1:36:41] Speaker 3: you know, four hundred thousand years ago, so under a million.
[1:36:45] Speaker 3: These populations are something else, the Homo erectus two million
[1:36:49] Speaker 3: years ago that made it to Europe is Homo erectus
[1:36:52] Speaker 3: by eight hundred thousand years ago. In Asia, Homo erectus
[1:36:56] Speaker 3: is persisting as its own thing, and it's also leaving
[1:36:58] Speaker 3: Denisovans around the same time. Just under a million years
[1:37:01] Speaker 3: You've got Denise Evans in Asia, You've got Neanderthals in Europe,
[1:37:05] Speaker 3: you've got Homo floresiensis, those little three foot tall hobbit
[1:37:08] Speaker 3: guys are in the islands of Floras of Indonesia. And
[1:37:11] Speaker 3: then back in Africa, you've still got Homo erectus persisting,
[1:37:16] Speaker 3: and eventually, at approximately three hundred thousand years ago, so
[1:37:21] Speaker 3: younger than Neanderthals, you start to see the characteristics that
[1:37:24] Speaker 3: define Homo sapiens from Homo erectus in East Africa right
[1:37:29] Speaker 3: around modern day Ethiopia, and this hominin Homo sapiens is
[1:37:33] Speaker 3: going to leave Africa again. What's cool is that we
[1:37:36] Speaker 3: have evidence that Homo sapiens tried to leave Africa several times. Right,
[1:37:40] Speaker 3: we have these incursions where we find Homo sapiens, you know,
[1:37:43] Speaker 3: just outside Africa in the Middle East at like one
[1:37:46] Speaker 3: hundred you know, two hundred thousand years ago thereabouts, and
[1:37:49] Speaker 3: then it disappears from the region, almost like Homo sapiens
[1:37:52] Speaker 3: is getting out, failing at establishing a population or perhaps
[1:37:56] Speaker 3: being beaten out by other hominins that already lived there.
[1:37:59] Speaker 3: But by seven thousand years ago, under one hundred thousand
[1:38:02] Speaker 3: years ago, where all of these other hominins are still
[1:38:04] Speaker 3: living in, you know, their relative regions. Homo sapiens are
[1:38:09] Speaker 3: species which is defined very specifically by a chin, so
[1:38:13] Speaker 3: specifically this and I'll get my skulls. I'll get my
[1:38:15] Speaker 3: skulls to.
[1:38:16] Speaker 2: Show you a uh, just to send you. Don't here
[1:38:19] Speaker 2: every day, I'm gonna get my skulls to show you.
[1:38:21] Speaker 2: But it's what I love about you. Go ahead, go.
[1:38:24] Speaker 3: Ahead, yeah yeah, yeah, yeah, yeah yeah. When we're defining
[1:38:28] Speaker 3: water Homo sapiens to the e inclusive of all these
[1:38:30] Speaker 3: other big brain hominins that are using a lot of
[1:38:32] Speaker 3: the same tools at the time, there are only a
[1:38:34] Speaker 3: couple of physical characteristics that make us Homo sapiens and
[1:38:37] Speaker 3: make them something else. The first is we got a little
[1:38:40] Speaker 3: bitty teeth even compared to these other guys. Our teeth
[1:38:42] Speaker 3: are smaller. We have a chin. So when I hold
[1:38:44] Speaker 3: these two side by side. You can see this little
[1:38:46] Speaker 3: bony shelf here that Neanderthals don't have. They're mandible, just
[1:38:51] Speaker 3: ends on a cliff, right, whereas ours jets out into
[1:38:54] Speaker 3: a little chin. We have really rounded skulls, rounded cranya.
[1:38:59] Speaker 3: I guess it's compared to other hominins. So when you
[1:39:02] Speaker 3: look at our skull, it makes this nice round, globular shape,
[1:39:06] Speaker 3: whereas with Neanderthals they have a skull that is long
[1:39:11] Speaker 3: and low, sort of stretches out backwards. They have a
[1:39:15] Speaker 3: skull that's long and low where it stretches out backwards,
[1:39:17] Speaker 3: almost like you've taken a human skull, pinched it and
[1:39:20] Speaker 3: pulled it backwards. Right, So humans have that really round one.
[1:39:24] Speaker 3: Neanderthals don't. And then when you look at their faces,
[1:39:27] Speaker 3: Homo sapiens has a forehead. Right, If you tried to
[1:39:30] Speaker 3: put a ball cap on this Neanderthal, they don't have
[1:39:33] Speaker 3: a forehead to hold it there, It's gonna fly off
[1:39:35] Speaker 3: in the wind. Whereas humans have really expanded that frontal
[1:39:39] Speaker 3: lobe upwards. Right, We've got this massive forehead that we
[1:39:42] Speaker 3: can fit a ball cap on our head, and our
[1:39:45] Speaker 3: skulls are sort of short and The argument goes that
[1:39:48] Speaker 3: Neanderthals were brilliant, right, like, they had these big brains,
[1:39:52] Speaker 3: that they were capable of a lot, but that they
[1:39:54] Speaker 3: the parts of their brains that they expanded were different
[1:39:56] Speaker 3: than the parts of the brains that Homo sapiens would expand.
[1:39:59] Speaker 3: So Neanderthals would expand the occipital region, this region in
[1:40:02] Speaker 3: the back part of the reason why I got that long,
[1:40:04] Speaker 3: low skull. They would have kicked our butts and any
[1:40:06] Speaker 3: kind of like hand eye coordination based sport, which would
[1:40:10] Speaker 3: make them probably incredible hunters, but their higher executive functions
[1:40:15] Speaker 3: were less developed, that's your argument than Homo sapiens, which
[1:40:18] Speaker 3: really put a lot of effort into expanding that frontal lobe,
[1:40:22] Speaker 3: which is like critical thinking and you know, things of
[1:40:24] Speaker 3: that nature. The argument goes that as Homo sapiens leaves
[1:40:27] Speaker 3: Africa about seventy thousand years ago, is when it's finally
[1:40:30] Speaker 3: successful at reaching all of these other locations, and very
[1:40:34] Speaker 3: shortly after Homo sapiens shows up in Europe, for example,
[1:40:38] Speaker 3: Neanderthals disappear forever they go extinct. Homo sapiens makes it
[1:40:41] Speaker 3: there at like forty five thousand years ago, Neanderthals are
[1:40:44] Speaker 3: gone by forty Right, we do the same thing out east.
[1:40:48] Speaker 3: We do the same thing when we reach Indonesia, where
[1:40:49] Speaker 3: Homo sapiens goes, silence follows. Community of the communities of
[1:40:55] Speaker 3: these other hominists disappear. Now we're not sure whether or
[1:40:59] Speaker 3: not there's a comparison that can be drawn to the
[1:41:02] Speaker 3: arrival of Homo sapiens and the extinction of these their hominins,
[1:41:05] Speaker 3: like because we're trying to kill them, right, The alternative
[1:41:08] Speaker 3: explanation is that you know, we're arriving in these locations
[1:41:11] Speaker 3: as the climate is changing. That's part of what's allowing
[1:41:14] Speaker 3: us to sort of make it into these new zones
[1:41:16] Speaker 3: with relative ease. That might be what finally let us
[1:41:19] Speaker 3: get there. But as we're getting there, humans have a
[1:41:23] Speaker 3: very different social organization that we can tell from the
[1:41:26] Speaker 3: genetics of deanderthals versus humans. Right, we know that we
[1:41:30] Speaker 3: organize ourselves differently because the Andertholls were super inbred at
[1:41:34] Speaker 3: the end of their tenure. Humans were not. We lived
[1:41:36] Speaker 3: according to our genetics and really big groups that you know,
[1:41:39] Speaker 3: collaborated and cooperated, whereas the androthals lived in smaller groups
[1:41:43] Speaker 3: that were kind of isolated from one another, which meant
[1:41:46] Speaker 3: that when the climate changed and humans rolled up into
[1:41:49] Speaker 3: the area, we were maybe just better equipped to deal
[1:41:52] Speaker 3: with the change because of our big groups, better critical thinking,
[1:41:56] Speaker 3: you know, in propensity to innovate as compared to Deanderthals.
[1:42:00] Speaker 3: And they went extinct and we didn't.
[1:42:02] Speaker 2: Well, stupid question, how did we get from that continent
[1:42:06] Speaker 2: to this continent?
[1:42:07] Speaker 3: Yeah, I mean as the ice ages come and go,
[1:42:10] Speaker 3: as glacial incursions you know, reached down into you know,
[1:42:13] Speaker 3: up from the poles, certain regions in the North Freeze.
[1:42:17] Speaker 3: And the argument goes is that there's a land bridge
[1:42:20] Speaker 3: that connects just the very very western portion of the
[1:42:24] Speaker 3: United States of Alaska with the very eastern portion of Russia,
[1:42:29] Speaker 3: so that the hominins that were up there could basically
[1:42:31] Speaker 3: take this land bridge walk across all the way over
[1:42:35] Speaker 3: to North America and then down and expand outwards, you know,
[1:42:39] Speaker 3: from like twenty thirty thousand years ago to present. But
[1:42:45] Speaker 3: there are arguments, and I don't know how much weight
[1:42:48] Speaker 3: these hold, because it's you know, I study the more
[1:42:50] Speaker 3: distant past than recent humans and recent human settlements. That's
[1:42:54] Speaker 3: not really my area. I study the more ap looking things.
[1:42:58] Speaker 3: But there are arguments that go that you may have
[1:43:00] Speaker 3: had humans Homo sapiens getting into North and South America
[1:43:04] Speaker 3: even earlier than like twenty to thirty thousand years ago.
[1:43:07] Speaker 3: And there's even a claim that is not super well
[1:43:09] Speaker 3: supported in my opinion, that there's evidence of humans using
[1:43:13] Speaker 3: tools there like one hundred thousand years ago, in which
[1:43:17] Speaker 3: case it wouldn't have been humans. It wouldn't have been
[1:43:19] Speaker 3: Homo sapiens we were still in Africa, would have been
[1:43:21] Speaker 3: something else that managed to make their way there and
[1:43:23] Speaker 3: then not establish a population and die out.
[1:43:27] Speaker 2: So many of the problems that we have as gentle
[1:43:30] Speaker 2: and modern names are actually evidence that we did evolve. Specifically,
[1:43:34] Speaker 2: we're talking about the large skull, the big brain case
[1:43:38] Speaker 2: these you know, the heavier part of the you know,
[1:43:41] Speaker 2: our torsos and whatnot, and the stresses that those put
[1:43:43] Speaker 2: on bodies that weren't originally you know, accommodating those types
[1:43:49] Speaker 2: of things. You want to speak to how the big
[1:43:52] Speaker 2: brains of modern day humans actually reveals that we are evolved.
[1:43:56] Speaker 3: Yeah, I mean it's not even just big brains, right,
[1:43:58] Speaker 3: We're losing our wisdom teeth. This is something that every
[1:44:00] Speaker 3: previous hominin had and always had the wisdom teeth are
[1:44:03] Speaker 3: disappearing in humans because we're not using them as much.
[1:44:07] Speaker 3: Why do we have a tailbone that looks exactly like
[1:44:09] Speaker 3: a chimpanzee's tailbone that looks exactly like a gorillas and
[1:44:13] Speaker 3: an orangutans and a gibvens. If all of us didn't
[1:44:15] Speaker 3: descend from something that used to have a tail, right,
[1:44:18] Speaker 3: you could just put a spur there. But no, we
[1:44:20] Speaker 3: actually have tail vertebrae. They're just tiny and they help
[1:44:24] Speaker 3: hold up our pelvic floor. But this is developmentally something
[1:44:27] Speaker 3: that used to be a tail. Right, we have the
[1:44:30] Speaker 3: same hands. Our hands have the primitive proportions of earlier apes. Right,
[1:44:36] Speaker 3: this long thumb and shorter fingers. This looks like a
[1:44:38] Speaker 3: proconsole hand. It's just slightly more dextrous. Thanks to our
[1:44:42] Speaker 3: larger brains. We have tons of different random features that
[1:44:47] Speaker 3: are super primby Right, like I mentioned earlier, we were
[1:44:51] Speaker 3: able to hold our hands directly above our head, which
[1:44:53] Speaker 3: is really beneficial to us. But this shows up first
[1:44:56] Speaker 3: in very very primitive apes for suspension below the branches.
[1:45:01] Speaker 3: We have all of the same regions of the brain
[1:45:04] Speaker 3: that a chimpanzee has. We just emphasize them in different ways.
[1:45:07] Speaker 3: We have all of the same bones and muscles as
[1:45:09] Speaker 3: these guys do, we just emphasize them in different ways. We're,
[1:45:13] Speaker 3: you know, in a modified Miocene ape and I think
[1:45:17] Speaker 3: that's super wonderful in a lot of different ways. I mean,
[1:45:21] Speaker 3: I find it absolutely awe inspiring.
[1:45:25] Speaker 2: You know.
[1:45:25] Speaker 3: I think that that's humbling, but in a most wonderful way,
[1:45:28] Speaker 3: because in the same way that it's humbling it it's
[1:45:30] Speaker 3: sort of I don't think of it as lowering us
[1:45:32] Speaker 3: to the level of everything else. I think of it
[1:45:34] Speaker 3: as elevating everything to our level and seeing this as
[1:45:38] Speaker 3: a beautifully connected tree of life of which we get
[1:45:42] Speaker 3: to be a part.
[1:45:43] Speaker 2: If I share that photograph of the human finger and
[1:45:46] Speaker 2: the I don't know the chimp finger that shows the fingerprint,
[1:45:50] Speaker 2: Is it a chimp that had the fingerprint. You've probably
[1:45:52] Speaker 2: seen it floating around that connects us to the other primates.
[1:45:56] Speaker 3: Yes, well, yeah, they have fingerprints. We have fingerprints, right,
[1:45:59] Speaker 3: I mean, they have fingernails. We have fingernails. They grow
[1:46:03] Speaker 3: you know, in bonobos, which are close relative to chimps,
[1:46:05] Speaker 3: they grow head hair longer than the hair on the
[1:46:07] Speaker 3: rest of their bodies. We have the same amount of
[1:46:10] Speaker 3: body hairs, especially folks with European ancestry to some degree, right,
[1:46:16] Speaker 3: is that we have the same amount of hairs on
[1:46:17] Speaker 3: our bodies. They're just finer, right, Like if you thickened
[1:46:20] Speaker 3: up my arm hair, it would look like a chimparm.
[1:46:22] Speaker 3: It's just everything about us is just a tweaked version
[1:46:26] Speaker 3: of them.
[1:46:27] Speaker 2: Well, this is what happens when I contact my friend
[1:46:31] Speaker 2: Erica and say, hey, can we chat for forty five minutes?
[1:46:33] Speaker 2: Because it's never forty five.
[1:46:35] Speaker 3: Minutes, never forty minutes.
[1:46:36] Speaker 2: I can't recall a conversation where I've seen a more
[1:46:39] Speaker 2: clear connecting of the dots in regard to human evolution,
[1:46:44] Speaker 2: which was the goal. So I'm happy to spend the
[1:46:46] Speaker 2: lengthy amount of time. I'm going to go and like,
[1:46:49] Speaker 2: donate to your channel for the time that you gave
[1:46:51] Speaker 2: to us, Let me support you in some way, let
[1:46:54] Speaker 2: me let me give back, Let me bless you in
[1:46:57] Speaker 2: the Lord Erica for your time. Any finals, we went
[1:47:01] Speaker 2: through the list of skulls, et cetera. But is there
[1:47:03] Speaker 2: anything we missed or you want to put a cap
[1:47:05] Speaker 2: on it? What do you think?
[1:47:06] Speaker 3: Yeah, I just want to sort of summarize that we've
[1:47:09] Speaker 3: walked through seven million years of history, and insofar as
[1:47:13] Speaker 3: one can briefly touch on them, briefly touched on early
[1:47:16] Speaker 3: hominins like sailanthropists and Artiepithecus, and we've talked about the Australopiths,
[1:47:20] Speaker 3: and we've talked about the rise of Genus Homo. We
[1:47:23] Speaker 3: completely skipped paranthropists because we didn't have time. But you know,
[1:47:25] Speaker 3: this is another group of hominins that was upright just
[1:47:29] Speaker 3: like we are, but they sort of maintained those small
[1:47:31] Speaker 3: brains and they've lived alongside Genus Homo for you know,
[1:47:34] Speaker 3: millions of years. We've talked about what changed and when
[1:47:37] Speaker 3: it changed, and how this was set out as a
[1:47:39] Speaker 3: prediction before a single hominin fossil was ever discovered and
[1:47:43] Speaker 3: formally talked about, you know, by Darwin and Huxley in
[1:47:47] Speaker 3: the mid eighteen hundreds, mid to late eighteen hundreds. That's
[1:47:50] Speaker 3: how science operates. It had we had this very clear prediction.
[1:47:53] Speaker 3: Do we see morphologic change over geologic time of an
[1:47:56] Speaker 3: ancient Miocene ape moving up to anatomically modern almostatebeans. The
[1:48:00] Speaker 3: answer is yes. And then some we see the emergence
[1:48:04] Speaker 3: of the traits that are required for bipedalism. Emerge slowly
[1:48:09] Speaker 3: over geologic time, mosaics on mosaics on mosaics in different organisms.
[1:48:14] Speaker 3: As we move up to Australopithecus. By then we've got
[1:48:16] Speaker 3: you know, bona fide bipeds and we start to see
[1:48:19] Speaker 3: the emergence of big brains alongside them, right, these brains
[1:48:22] Speaker 3: emerging and developing at the same time as we're seeing
[1:48:25] Speaker 3: the advancement of stone tools and the emergence of omnivory
[1:48:30] Speaker 3: and hunting in humans and in hominins before us. And
[1:48:34] Speaker 3: this is all easily accessible to anybody who's curious about it,
[1:48:39] Speaker 3: and wonderfully confirms predictions made, you know, centuries ago by
[1:48:43] Speaker 3: people who all they had was a hypothesis, and they said,
[1:48:46] Speaker 3: you know, if we're right, and humans have all from
[1:48:48] Speaker 3: amar basic like, this is what it should look like.
[1:48:51] Speaker 3: And that has come to pass, and every single year
[1:48:54] Speaker 3: is cemented further and further and further by additional discoveries
[1:48:58] Speaker 3: by hardworking and passionate people that I am so lucky
[1:49:02] Speaker 3: to call colleagues.
[1:49:04] Speaker 2: I am into the audiobook the book Sapiens. I'm sure
[1:49:08] Speaker 2: you're familiar with the history. Is there a book? I mean,
[1:49:12] Speaker 2: I hate to I mean, I just want to try
[1:49:14] Speaker 2: to hone things down. But a lot of people may
[1:49:17] Speaker 2: not be visual learners or audio learners. Maybe they're readers.
[1:49:20] Speaker 2: Is there a book that sort of summarizes much of this?
[1:49:23] Speaker 3: Gosh, human evolution is so complicated. It depends on what
[1:49:27] Speaker 3: part you're interested in learning about. So if you want
[1:49:28] Speaker 3: to learn about the bipedalism stuff that I've talked about,
[1:49:31] Speaker 3: First Steps by Da Silva is wonderful. He studies specifically
[1:49:35] Speaker 3: the evolution of bipedalism and specifically prominent feet up through
[1:49:40] Speaker 3: time and it basically goes through what I've talked about here,
[1:49:42] Speaker 3: but in far more detail, and then sort of halt said,
[1:49:45] Speaker 3: as we get up to a more erectus because everything's
[1:49:47] Speaker 3: by pedal and really really good at it. By that point,
[1:49:50] Speaker 3: if you want to talk about the period of time
[1:49:51] Speaker 3: that's before the split of humans and chimpanzees and how
[1:49:54] Speaker 3: we still bear all of the characters that makes an
[1:49:57] Speaker 3: ape an ape, and that makes a great ape a
[1:49:59] Speaker 3: great ape, you can read David Begun's The Real Planet
[1:50:03] Speaker 3: of the Apes, which talks about the Miocene when apes
[1:50:05] Speaker 3: first evolved and you know what makes them apes, as
[1:50:08] Speaker 3: well as Peter Andrews and Apes view of human evolution
[1:50:12] Speaker 3: if you're curious, is to like, why are Neanderthals extinct
[1:50:15] Speaker 3: and we're still here? And what made us similar and
[1:50:17] Speaker 3: what made us different? You can read Kindred by Rack Psychs,
[1:50:20] Speaker 3: which is an absolutely She's really like four figure forerunning
[1:50:25] Speaker 3: figure on Neanderthals in general, and her book Kindred is
[1:50:29] Speaker 3: phenomenal in how it outlines just how weird and fascinating
[1:50:34] Speaker 3: and interesting these close relatives to us were and how
[1:50:37] Speaker 3: we interacted with each other. All of these are really
[1:50:41] Speaker 3: wonderful texts if you just want to get started, and
[1:50:43] Speaker 3: they're all pop science, so they're really easy reads in
[1:50:45] Speaker 3: my opinion, and I hope some of you guys check
[1:50:48] Speaker 3: them out.
[1:50:49] Speaker 2: You know what's amazing about you? You just vamp so
[1:50:51] Speaker 2: much of this. Right. I'm sitting here, I've got notes
[1:50:54] Speaker 2: and show prep and I'm trying to guide everything, and
[1:50:57] Speaker 2: you just go, It's awesome, impressive. Erica is a palaeontologist.
[1:51:03] Speaker 2: She is host of the Gutsig Given channel. I will
[1:51:06] Speaker 2: link to everything in the description box and I'm going
[1:51:09] Speaker 2: to go make a freaking donation to your channel because
[1:51:11] Speaker 2: you have given so much to us today. You've just
[1:51:13] Speaker 2: told the story at least in a rudimentary form, in
[1:51:16] Speaker 2: a way that we can understand and play along. Erica,
[1:51:19] Speaker 2: so good to talk to you.
[1:51:20] Speaker 3: Thanks again, oh Seth, thank you for letting me be here.
[1:51:24] Speaker 3: I truly had a blast. Remember you know, I'm giving
[1:51:27] Speaker 3: my best effort at being brief on this. There's so
[1:51:30] Speaker 3: much more out there. There are so many other hypotheses
[1:51:32] Speaker 3: I've talked about, hypotheses that I find convincing. There's so
[1:51:35] Speaker 3: much more to get into. If you find this fascinating
[1:51:38] Speaker 3: and if you want to learn more so I can't
[1:51:40] Speaker 3: stress enough. You know, fact check me. Creationists out there,
[1:51:43] Speaker 3: go go see for yourself. I love to hear your opinion.
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