# Of lice and men

An episode of [Daniel and Kelly’s Extraordinary Universe](https://invisiblenetwork.ai/podcast/1436616330), 9 Jul 2026, 53 min.

Audio: https://podtrac.com/pts/redirect.mp3/traffic.omny.fm/d/clips/e73c998e-6e60-432f-8610-ae210140c5b1/f5d5fac6-77be-47e6-9aee-ae32006cd8c3/63fca90d-2ab0-4c4c-91b7-b480002fb7c6/audio.mp3?utm_source=Podcast&in_playlist=b26cbbeb-86eb-4b97-9b34-ae32006cd8d6

Daniel and Kelly explore what lice can teach us about human evolution, and the role lice have played in some of humanity's most devastating wars. See omnystudio.com/listener for privacy information.

## Transcript

[0:00] Speaker 1: Howdy extraordinaries. Today we're discussing human lice. If you're a parent,
[0:05] Speaker 1: you may be at the stage in your life where
[0:07] Speaker 1: you're worried about kids bringing home lice from school. But
[0:10] Speaker 1: back in your wilder days, if you had wilder days,
[0:15] Speaker 1: there may have been another kind of lice found out
[0:18] Speaker 1: a different part of the body that you worried about.
[0:21] Speaker 1: Maybe it made you feel let's say, crabby. We're talking
[0:26] Speaker 1: about both kinds of lice today and some historically catastrophic
[0:31] Speaker 1: diseases that lice frequently caused in the past. So decide
[0:35] Speaker 1: if this episode is appropriate for you or young ears
[0:40] Speaker 1: that might also be listening. Thanks When you grab a
[0:51] Speaker 1: lice comb and spend hours picking through your kid's hair
[0:54] Speaker 1: to remove those little buggers, you're engaging in a time
[0:58] Speaker 1: honored human tradition that stretches for millennia. Direct evidence of
[1:04] Speaker 1: human head lice goes back ten thousand years, and we
[1:07] Speaker 1: found six five hundred year old head lice combs in Egypt.
[1:13] Speaker 1: But we've probably had head lice even earlier than that,
[1:16] Speaker 1: perhaps even since the dawn of our species. So if
[1:19] Speaker 1: this pest has been with us during our entire journey
[1:23] Speaker 1: as a species, Then can studying it tell us anything
[1:26] Speaker 1: about our past? Or can studying it at least tell
[1:30] Speaker 1: us how to get rid of it better? Welcome to
[1:33] Speaker 1: Daniel and Kelly's lousy universe.
[1:49] Speaker 2: Hi. I'm Daniel. I'm a particle physicist who likes to
[1:51] Speaker 2: think about aliens, and my family's had lice more times
[1:55] Speaker 2: than I can count.
[1:56] Speaker 3: Hello. I'm Kelly Waiter Smith.
[1:58] Speaker 1: I study parasites and and my family has never had lice.
[2:04] Speaker 2: But we have had fleas, not even once in a
[2:07] Speaker 2: life's time.
[2:08] Speaker 3: Nahaa, what a lousy joke.
[2:13] Speaker 2: It's not even my joke. It's literally the name of
[2:15] Speaker 2: the place we took our kids to get them de loused.
[2:18] Speaker 1: Oh man, you know, I don't know how we avoided
[2:21] Speaker 1: it because my daughter like puts on other people's hats
[2:24] Speaker 1: and like, well, you know, she'll be like, oh yeah,
[2:26] Speaker 1: I was like, your hair looks brushed?
[2:28] Speaker 3: How did that happen?
[2:28] Speaker 1: And she's like, oh, I bird a friend's brush at school,
[2:31] Speaker 1: And I'm like, God, somehow we have managed to completely
[2:34] Speaker 1: avoid lice. I don't know how. It blows my mind.
[2:37] Speaker 2: Maybe something about your remote living on your enclave, escaping humanity, you.
[2:41] Speaker 3: Know, Yeah, but I don't know.
[2:43] Speaker 1: She still goes to school where they like, I don't know,
[2:44] Speaker 1: it's swhear they greet each other by like licking each
[2:47] Speaker 1: other's hands and then rubbing their heads together, Like kids
[2:50] Speaker 1: are weird and gross.
[2:54] Speaker 2: Well, I was going to ask you about whether your
[2:56] Speaker 2: family had lice, but now I want to hear all
[2:58] Speaker 2: about how you got fleas. Which animal on the farm
[3:01] Speaker 2: passed them to you.
[3:02] Speaker 3: Oh, this was when we lived in a city. This
[3:05] Speaker 3: blew my mind.
[3:06] Speaker 1: Okay, So we lived in Houston and we had two cats,
[3:09] Speaker 1: and we had just had our second baby. Our second
[3:12] Speaker 1: baby just came home, so we were like out of
[3:14] Speaker 1: our minds with like exhaustion and like you know, the
[3:17] Speaker 1: delirium that comes along with having a new baby at home.
[3:20] Speaker 1: And it was winter, and so I forgot to give
[3:23] Speaker 1: our cats their flea medication. But they're one hundred percent
[3:26] Speaker 1: indoor cats.
[3:28] Speaker 3: And it was winter, so it was.
[3:30] Speaker 2: Like winter in Houston.
[3:31] Speaker 3: Winter in Houston. Yeah, winter in Houston.
[3:33] Speaker 2: So what's the relevance of winter, I'm not following.
[3:35] Speaker 1: I think there's fewer fleas outside in the winter. I
[3:38] Speaker 1: don't know.
[3:40] Speaker 2: I probably fleas all migrate to Mexico in the winter.
[3:44] Speaker 3: Or something yes, no, no, I guess I don't know
[3:46] Speaker 3: much about fleas.
[3:47] Speaker 1: But somehow, in my head it's less likely that someone's
[3:50] Speaker 1: gonna walk around in the grass and bring a flea
[3:53] Speaker 1: that could infect a cat back into your house or something,
[3:56] Speaker 1: and then they're gonna find your cat anyway. Somehow, Well,
[4:00] Speaker 1: my one hundred percent indoor cats got fleas, and I
[4:04] Speaker 1: didn't realize it until I was changing a diaper and
[4:08] Speaker 1: I saw something hop wow, and there was a flea
[4:12] Speaker 1: on my kid. And I was like, I am the
[4:14] Speaker 1: worst mother in the whole world, and so immediately you're not.
[4:18] Speaker 2: But that doesn't nominate you for being the best money.
[4:22] Speaker 3: That was an emotional roller coaster there. I felt a
[4:25] Speaker 3: little better, and then I felt real bad again.
[4:27] Speaker 2: And so it's hard to compliment somebody for having fleas
[4:30] Speaker 2: on their babies.
[4:30] Speaker 3: You didn't have to like rank me at all.
[4:33] Speaker 1: I could just tell the story and anyway, well, your
[4:36] Speaker 1: family has had life an uncountable number of times.
[4:39] Speaker 3: So I don't think either one of us are winning
[4:41] Speaker 3: parents of the Year.
[4:44] Speaker 2: I'm not suggesting it's like seventeen thousand. I'm just saying
[4:47] Speaker 2: it's often enough that I didn't even keep track it's
[4:50] Speaker 2: like two or three times. I'm not even sure. It
[4:52] Speaker 2: just felt like a routine. I remember going back to
[4:55] Speaker 2: once in a Lifetime and being like, I thought we
[4:57] Speaker 2: were supposed to only be here once in a lifetime.
[5:02] Speaker 1: Well, that's false advertising, because you can get lice over
[5:04] Speaker 1: and over and over again.
[5:06] Speaker 2: That's true. But I do love how this whole field
[5:08] Speaker 2: is riddled with terrible puns.
[5:10] Speaker 1: Yeah yeah, well, and I think from lice come many
[5:14] Speaker 1: words like nitpicking. Oh yeah, I mean we've had, you know,
[5:18] Speaker 1: like the Bible has stories about lice as a plague
[5:22] Speaker 1: like it.
[5:22] Speaker 3: This has been part of our history for a really.
[5:25] Speaker 1: Long time, you know, Like we find evidence of lice
[5:28] Speaker 1: on mummies, which is amazing because lace shouldn't preserve well, right,
[5:31] Speaker 1: So the fact that you find any of them probably
[5:33] Speaker 1: means there were loads of them.
[5:35] Speaker 2: Are they also individually wrapped in little mummy cloths? Ah?
[5:39] Speaker 1: No, no, because nobody was trying to bring them with
[5:41] Speaker 1: them into the afterlife. But but there's an old document
[5:45] Speaker 1: called the Papyrus Ebers that's like, you know, an ancient
[5:48] Speaker 1: Egyptian document that has a recipe for how.
[5:51] Speaker 3: To make like a thing to kill lice.
[5:54] Speaker 1: And so we've We've been dealing with this for a
[5:56] Speaker 1: long time, probably from like literally.
[5:58] Speaker 3: The beginning of our species, which we're gonna get to interesting.
[6:01] Speaker 2: Well, I've had my own personal evolution with my feelings
[6:04] Speaker 2: about life because I used to feel like, oh my god,
[6:06] Speaker 2: that is the creepiest thing. You have, these little animals.
[6:08] Speaker 2: They're crawling all over you. They're like mating and pooping
[6:11] Speaker 2: and doing all this stuff. Yuck. But you know, then
[6:15] Speaker 2: I'm at Katrina and I got married to her, and
[6:17] Speaker 2: now I fully understand that every surface of my body
[6:21] Speaker 2: is a little ecosystem and I'm always going to be
[6:24] Speaker 2: covered in little critters, little microbes doing this that and
[6:27] Speaker 2: the other. And lice are just you know, they're like
[6:30] Speaker 2: the elephants in that forest, and like whatever.
[6:32] Speaker 1: Man, I totally disagree with you, but I don't want
[6:37] Speaker 1: I don't want to dissuade you from this story.
[6:39] Speaker 3: You've told yourself to make yourself feel better. So I
[6:42] Speaker 3: think we should move on to the question that prompted
[6:44] Speaker 3: in this episode.
[6:48] Speaker 2: Let's not dig into dangel psychological issues. Let's answer questions
[6:51] Speaker 2: from listeners. So, Kelly, why are we talking about life today?
[6:55] Speaker 1: Well, we have this amazing discord community and You can
[6:58] Speaker 1: join us by going to Daniel and Kelly dot org
[7:01] Speaker 1: and clicking on the link to join our discord community.
[7:04] Speaker 1: And in Discord, user Bauer family told this story that
[7:09] Speaker 1: they sort of vaguely remembered about how the divergence time
[7:13] Speaker 1: between pubic lice and head lice can tell you about
[7:19] Speaker 1: when we became hairless, because when we lost the hair
[7:24] Speaker 1: on you know, like our bellies and our shoulders or whatever,
[7:26] Speaker 1: there now was like a big gulf between you know,
[7:30] Speaker 1: any lice that are in your hair and any lice
[7:32] Speaker 1: that are in your pubic region. And actually the hair
[7:34] Speaker 1: in your pubic region is quite different in like texture
[7:37] Speaker 1: and thickness and stuff than the hair on your head.
[7:40] Speaker 1: And so the idea here is if you could date
[7:41] Speaker 1: the divergence between those two life species, you can figure
[7:45] Speaker 1: out when humans became mostly hairless.
[7:49] Speaker 2: This is like having a population of animals on some
[7:52] Speaker 2: continent and then it splits into two and you can
[7:54] Speaker 2: track them individually exactly.
[7:56] Speaker 3: Yes.
[7:56] Speaker 1: Allopatrick's speciation is when you get like a physical barrier
[7:59] Speaker 1: between what was once one population. Now it becomes too
[8:02] Speaker 1: and over time they separate enough that they become different species,
[8:06] Speaker 1: and you know, maybe can't even breed together anymore. Wow,
[8:09] Speaker 1: So this was like a story that they had heard
[8:12] Speaker 1: and they wanted to know more.
[8:14] Speaker 3: It's totally wrong, which we're gonna get totally.
[8:17] Speaker 4: Wrong, totally wrong.
[8:18] Speaker 2: It sounds like such a cool science story. And I
[8:21] Speaker 2: was going to make all these jokes about pubic island.
[8:23] Speaker 1: Well you still can't, because we're gonna still talk about
[8:25] Speaker 1: pubic lice.
[8:26] Speaker 3: And they're interesting, but yet, like.
[8:28] Speaker 1: In general, as I was going through and doing the research,
[8:30] Speaker 1: I realized they were all of these things I had
[8:32] Speaker 1: heard about lice that when you dig into the research,
[8:34] Speaker 1: are totally not substantiated by the science. And so we
[8:37] Speaker 1: are going to be dispelling lousy stories today on DKA.
[8:43] Speaker 2: Well is this going to be a wet blanket episode
[8:45] Speaker 2: or are we going to come away with an even
[8:47] Speaker 2: more interesting, actually substantiated science story.
[8:51] Speaker 1: Yeah, those things are not mutually exclusive, so we're going
[8:54] Speaker 1: to do both.
[8:55] Speaker 2: So let's dig into it. Start us off with an
[8:57] Speaker 2: introduction to lice, because I think I have this idea
[9:00] Speaker 2: that lice are these basically tiny, little crawling critters, maybe
[9:04] Speaker 2: like a shrunken down version of a beetle that's living
[9:07] Speaker 2: on me.
[9:08] Speaker 3: Yes, so they don't have wings.
[9:10] Speaker 1: They can only like crawl, So fleas can jump, but
[9:13] Speaker 1: lice can only crawl. They're very slow moving, so pretty
[9:15] Speaker 1: much the only way they get from one host to
[9:18] Speaker 1: another is like physical contact, and so you need to
[9:21] Speaker 1: like maybe one get stuck in a hat and then
[9:23] Speaker 1: you put that hat on your head and now it
[9:25] Speaker 1: is on you. But they're not jumping from host to hosts.
[9:28] Speaker 2: And so how big are these things?
[9:30] Speaker 1: They're about the size of like a sesame seed or
[9:33] Speaker 1: a pencil tip, so they're tiny.
[9:35] Speaker 2: Oh oh, that's actually bigger than I thought. I thought
[9:37] Speaker 2: they're gonna be almost impossible to see.
[9:39] Speaker 1: No, no, no, I mean, I guess you offloaded the
[9:42] Speaker 1: job of nit picking your kids to once upon a
[9:47] Speaker 1: lice what was it, once in a lice time? Lots
[9:50] Speaker 1: of free advertising for once in a lifetime today.
[9:53] Speaker 3: But if you take like, you.
[9:55] Speaker 1: Know, a lice comb and you go through, you can see,
[9:58] Speaker 1: especially if you have dark hair. Yeah, you can see
[10:00] Speaker 1: the eggs which are even smaller, and then you can
[10:02] Speaker 1: see the adults and you can, you know, get them
[10:04] Speaker 1: out with a lice comb.
[10:05] Speaker 2: I see. And are these guys insects or are they
[10:09] Speaker 2: arthropods or something else? Like if you made this thing
[10:12] Speaker 2: like the size of a football, what would it look like?
[10:14] Speaker 1: Okay, so that they are arthropods and their insects, and
[10:17] Speaker 1: if you zoomed in so their bodies, you know, there's
[10:21] Speaker 1: like I think something like five thousand species of like
[10:25] Speaker 1: what you would maybe count as lice, but like for
[10:27] Speaker 1: human lice, you know, their bodies are some of them
[10:30] Speaker 1: kind of look football shaped the like base part of
[10:33] Speaker 1: their body, although pubic lice tend to be a little
[10:35] Speaker 1: bit more like flattened. But anyway, and then they've got
[10:38] Speaker 1: six appendages that stick out, and they've got sort of
[10:42] Speaker 1: like hooky hands that they used to like cling to
[10:45] Speaker 1: your hair to like hug your hair or hold onto it,
[10:48] Speaker 1: sort of like the way a sloth holds onto like
[10:50] Speaker 1: a tree branch. And then they've got like heads with antenna.
[10:54] Speaker 1: And they look pretty clear ish or like orange y
[10:59] Speaker 1: ish most of the time, unless they've got some a
[11:01] Speaker 1: blood meal, then they can be kind of red.
[11:03] Speaker 2: So do they look like tiny ticks basically ticks?
[11:06] Speaker 1: How would I say they're different? So the tick body
[11:09] Speaker 1: tends to be like more smooth, whereas a lice body
[11:12] Speaker 1: looks a little bit more like ridged to me.
[11:16] Speaker 2: All right, but they're tiny, little creepy crawlies. Yeah, And
[11:19] Speaker 2: you said something fascinating. You said, there's thousands of species
[11:22] Speaker 2: of lice, but not all of them are human lice.
[11:25] Speaker 2: How many species are there of human lice?
[11:28] Speaker 1: So there's two species of lice that you commonly find
[11:31] Speaker 1: on humans, and that's the head slash body louse. And
[11:35] Speaker 1: we're gonna spend a lot of time talking about that
[11:37] Speaker 1: slash a little bit later. It's a very important slash, okay.
[11:42] Speaker 2: But the different species of lice are connected to the
[11:45] Speaker 2: different species of a host's right, So like, yes, chimp
[11:48] Speaker 2: lice is different from human lice, is different from dog lice.
[11:50] Speaker 2: So I'm not gonna get lice from my dog, and
[11:53] Speaker 2: you weren't going to get lice from your cat.
[11:55] Speaker 3: That's right.
[11:55] Speaker 1: Well, so what the cat story? Those were fleas, right,
[11:59] Speaker 1: very different diferent. Actually, I know they don't sound different,
[12:02] Speaker 1: but like the fact that they can hop, I mean
[12:04] Speaker 1: their legs are like totally different.
[12:05] Speaker 2: I know, I remember the fleas and lice are different.
[12:07] Speaker 2: But I was making the point that, like, if your
[12:09] Speaker 2: cat had fleas and lice, you could get its fleas,
[12:11] Speaker 2: but not.
[12:12] Speaker 1: It's lyce yeah, yeah, we got their fleas, but if
[12:14] Speaker 1: they had had lice, we wouldn't have gotten their lice.
[12:16] Speaker 1: Yeah yeah, yeah, So lice tend to be very very
[12:19] Speaker 1: host specific, and you tend to find lice in two
[12:22] Speaker 1: different flavors.
[12:24] Speaker 3: It is the gross way of.
[12:25] Speaker 1: Saying that there are scavenger lice, which eat like dead
[12:30] Speaker 1: skin pieces and stuff. We don't have those kinds of
[12:33] Speaker 1: lice on human bodies, unfortunately, because what we have are
[12:37] Speaker 1: the sucking lice, which have like a thing that they
[12:40] Speaker 1: shove into your body so that they can suck blood.
[12:43] Speaker 3: And yeah, they're like feeding on blood.
[12:45] Speaker 2: So they're like crawling mosquitoes.
[12:47] Speaker 3: Yeah, they're like crawling mosquitos. But whereas mosquitoes.
[12:49] Speaker 1: Might take blood meals from multiple different people, your lice
[12:52] Speaker 1: are probably spending most of their life on you, unless
[12:54] Speaker 1: they jump to a partner that you have.
[12:58] Speaker 2: Well, I still prefer lice because mosquito leave you with
[13:00] Speaker 2: these itchy bites, and I'm always like, just take the
[13:03] Speaker 2: blood meal, don't leave me with the bite. Okay, But
[13:05] Speaker 2: but lyce don't give you itchy bites, do they?
[13:08] Speaker 3: Oh heck yeah they do.
[13:09] Speaker 1: Yeah, So okay, so life's bite and depending on how
[13:12] Speaker 1: your body responds to them, which is the same thing
[13:14] Speaker 1: with mosquitoes. You can get itchy, and in fact, for
[13:18] Speaker 1: head lice, like the biggest thing you worry about is
[13:22] Speaker 1: that somebody is going to scratchcratch, cratchratch, scratch, and then
[13:25] Speaker 1: get a secondary bacterial infection. And so it's not that
[13:28] Speaker 1: the lice are giving you a disease, but if you
[13:30] Speaker 1: like create a bunch of wounds on your head from
[13:32] Speaker 1: scratching and then bacteria gets in there, that could cause
[13:35] Speaker 1: its own problem.
[13:36] Speaker 4: Right.
[13:36] Speaker 2: Of course, having an itchy head is one of the
[13:38] Speaker 2: biggest clues that you might have lice.
[13:40] Speaker 1: Of course, yes, yeah, right, And so where is a
[13:42] Speaker 1: mosquito takes a blood meal from you and then goes
[13:44] Speaker 1: and lays her eggs somewhere else. Lice take a blood
[13:48] Speaker 1: meal from you and then they cement their eggs.
[13:51] Speaker 3: This is for head lice.
[13:52] Speaker 1: They cement their eggs to your hair and they stay
[13:55] Speaker 1: with you and then they hatch, and so you have
[13:58] Speaker 1: a population that, if you don't do anything about it,
[14:00] Speaker 1: over time, can multiply and become huge. Whereas one mosquito
[14:05] Speaker 1: bites you, they go away, maybe their kids will never
[14:07] Speaker 1: bite you. And so I think I'd rather have a
[14:09] Speaker 1: mosquito bite than a lice that might turn into a
[14:12] Speaker 1: community of lice wiener smith manor up there or something.
[14:17] Speaker 2: They got their own little farm. So, if every species
[14:20] Speaker 2: of animal has their own species of lice, and some
[14:23] Speaker 2: of these species have common ancestry, did the louse species
[14:27] Speaker 2: diverted at the same time as the hosts? How did
[14:30] Speaker 2: that work?
[14:30] Speaker 4: Yes?
[14:31] Speaker 1: Okay, so this is this is where we get into
[14:32] Speaker 1: like the fascinating evolutionary biology. Okay, So we have two
[14:35] Speaker 1: different species of lice on our body, which we've talked about.
[14:39] Speaker 1: Our head lice share a common ancestor with the lice
[14:43] Speaker 1: that you find on chimpanzees. So what that means is
[14:47] Speaker 1: about six million years ago we shared a common ancestor
[14:50] Speaker 1: with chimpanzees. When we split, both of those groups that
[14:56] Speaker 1: split had lice on them, and so over time, the
[14:59] Speaker 1: lice on chimps ended up evolving into like the chimp louse,
[15:02] Speaker 1: and the louse that was on you know what ended
[15:05] Speaker 1: up becoming humans or Homo sapiens evolved into pendiculous humanas so,
[15:10] Speaker 1: which is our human louse. And so the common ancestor
[15:15] Speaker 1: for those lice is from six million years ago, which
[15:19] Speaker 1: is about when chimpanzees and humans split.
[15:21] Speaker 3: Does that make sense?
[15:22] Speaker 2: All right, So chimps and humans split almost six million
[15:25] Speaker 2: years ago, and human head lice and chimp lice split
[15:28] Speaker 2: around the same time.
[15:29] Speaker 4: Yes, okay, right, I'm with you so far.
[15:31] Speaker 2: But there's another species of lice on humans, and we
[15:34] Speaker 2: haven't explained yet where that came from.
[15:36] Speaker 1: That's right, And I think I want to stay on
[15:38] Speaker 1: the head lice for a second and talk about what
[15:40] Speaker 1: headlights can tell us about human evolution.
[15:41] Speaker 3: But we will be back to the pubic lice, don't
[15:44] Speaker 3: you worry.
[15:46] Speaker 2: We will be visiting Pubic Island very shortly. But right
[15:49] Speaker 2: now we're staying on the continent of the head.
[15:51] Speaker 4: Okay, okay.
[15:52] Speaker 1: So when you look at the head lice, and you
[15:54] Speaker 1: collect head lice from all over the world, you see
[15:57] Speaker 1: something kind of weird, which is that they're seeing to
[16:00] Speaker 1: be something like five or six of what they call clades,
[16:04] Speaker 1: which is to say, if you look at them genetically,
[16:06] Speaker 1: you're like, oh, the lice over here, they're really closely related.
[16:10] Speaker 1: But the lice over here they look different. They're not
[16:13] Speaker 1: as closely related, they're not a different species. But what
[16:16] Speaker 1: we think was happening was that, Okay, chimpanzees and humans split,
[16:21] Speaker 1: but it's not like it's a straight line to Homo sapiens. Right,
[16:24] Speaker 1: there was Homo erectus and Neanderthals and Denisovans, and it
[16:28] Speaker 1: was really fun reading papers from before we had definitive
[16:32] Speaker 1: evidence that Neanderthals and Denisovans bread and so folks might
[16:36] Speaker 1: remember we had Nathan Lentz on the show to talk
[16:37] Speaker 1: about how we know from genetic evidence that humans were
[16:41] Speaker 1: breeding with Neanderthals, But what they think happened is that
[16:44] Speaker 1: like Neanderthals and homoerectus and Denisovans, they all had their
[16:48] Speaker 1: own lice, and for the most part, those lice were separated,
[16:53] Speaker 1: so they were starting to become different species. So there
[16:56] Speaker 1: was starting to become like a Neanderthal lice and a
[16:59] Speaker 1: Denisovan lice.
[17:00] Speaker 2: So the life's populations were drifting apart, the same way
[17:03] Speaker 2: the human populations were, but they weren't yet so far
[17:05] Speaker 2: apart they couldn't.
[17:06] Speaker 4: Interbreed exactly, right.
[17:09] Speaker 1: But then Homo sapiens started breeding with these other humans,
[17:13] Speaker 1: which we know happened, right, And so we think that
[17:15] Speaker 1: some of these clades are actually like the Neanderthal lice
[17:19] Speaker 1: jumping ship while the Neanderthals are going extinct, and so
[17:23] Speaker 1: like some of our clades might have come from like
[17:25] Speaker 1: Homo erectus, who were going extinct and we got them
[17:28] Speaker 1: when we like, you know, we're sharing a bed together
[17:31] Speaker 1: probably or I don't know, sharing hats.
[17:33] Speaker 3: Who knows if we had hats back then.
[17:34] Speaker 1: But so there's evidence in like the different clades of
[17:38] Speaker 1: headlicce that you find around the world of the different
[17:41] Speaker 1: kinds of species of humans that we sort of interacted
[17:45] Speaker 1: with in our past.
[17:46] Speaker 2: That's incredible. So we see evidence for human divergence and
[17:50] Speaker 2: recombination in our own genetic heritage and that's mirrored in
[17:55] Speaker 2: the lice. That's incredible.
[17:56] Speaker 1: Yeah, right, So I've seen papers that are claiming that
[18:00] Speaker 1: lice can teach us about human evolution. As far as
[18:03] Speaker 1: I can tell, head lice have been able to provide
[18:06] Speaker 1: additional support for what we already think is happening about
[18:09] Speaker 1: human evolution. But there's been nothing in the head lice
[18:12] Speaker 1: where we've seen something here and been like that definitely
[18:15] Speaker 1: means that humans must have done this, and then later
[18:18] Speaker 1: we found archaeological evidence for it. But still it's nice
[18:20] Speaker 1: because like, you know, you have data from one source,
[18:24] Speaker 1: and you feel much better if you have data from
[18:26] Speaker 1: a completely different source that's saying the same thing. And
[18:29] Speaker 1: so human head lice are helping us feel more confident
[18:33] Speaker 1: about these stories about like when our ancestors left Africa
[18:37] Speaker 1: and when we came back together again, and anyway, I
[18:40] Speaker 1: think that's pretty awesome.
[18:41] Speaker 2: Absolutely, and it's an important part of doing science.
[18:44] Speaker 1: Right.
[18:44] Speaker 2: You get a story from one place, you want to
[18:46] Speaker 2: see if another line of data tells the same story
[18:49] Speaker 2: or a different story, and if it's different, why is that?
[18:52] Speaker 2: And then there's a mystery to untangle. So it's always
[18:54] Speaker 2: good to check things in different directions and if they
[18:57] Speaker 2: line up and tell the same story, then yeah, you're
[18:58] Speaker 2: more confident in it. Though of course you could always
[19:01] Speaker 2: learn new stuff, that's right, So that's very cool.
[19:04] Speaker 1: Yeah yeah, Okay, So now let's take a break and
[19:06] Speaker 1: when we come back, we're going to go down under.
[19:08] Speaker 1: Sorry Australians, croy.
[19:30] Speaker 3: All right, we're back and we are moving from the
[19:33] Speaker 3: head to the pubic lice.
[19:36] Speaker 1: So this is where we are really digging into the
[19:40] Speaker 1: question from the listener. So the hypothesis here is that, okay,
[19:43] Speaker 1: we got our head lights from this common ancestor, and
[19:45] Speaker 1: then we went off being humans, and over time the
[19:50] Speaker 1: population of lice that we're living on us split into
[19:53] Speaker 1: two different islands, the hair that we have on our
[19:56] Speaker 1: head and then the hair that we have in our
[19:58] Speaker 1: pubic region. And that if you can date when that
[20:02] Speaker 1: split happened, that must tell you when we lost the
[20:05] Speaker 1: hair around like the middle part of our body.
[20:08] Speaker 2: Right, although not all of us are hairless in the
[20:10] Speaker 2: middle part of their body, right, you know, for some
[20:13] Speaker 2: of us, you could even say that there's a continuous,
[20:16] Speaker 2: you know, land bridge there from one kind of hair
[20:20] Speaker 2: to the other. Does this hypothesis rely on there being
[20:24] Speaker 2: like a really distinct break there.
[20:26] Speaker 1: Well, so that is not where things fall apart. But
[20:30] Speaker 1: that is a good point. And another point is that,
[20:32] Speaker 1: you know, which we've already mentioned, is that the hair
[20:34] Speaker 1: in those two different locations has very different thickness and consistency,
[20:38] Speaker 1: and so you find different grasping hands on the different
[20:43] Speaker 1: lice in the different regions because you sort of just
[20:45] Speaker 1: need different grappling hooks depending on where you're living. But
[20:49] Speaker 1: what's better evidence is the fact that actually your pubic
[20:52] Speaker 1: lice are not the direct ancestors of your head lice.
[20:55] Speaker 3: They are lice that we got, not.
[20:58] Speaker 1: From a quote cospeciation event where you and a common
[21:01] Speaker 1: ancestor split.
[21:03] Speaker 3: This is a host switch.
[21:05] Speaker 1: Oh do you want to guess where we got our
[21:06] Speaker 1: pubic lice from?
[21:07] Speaker 2: Hold on, So you're telling me that the pubic lice
[21:10] Speaker 2: are not a branch of the head lice which then
[21:12] Speaker 2: drifted off because they were separated by the ocean of
[21:16] Speaker 2: my belly. Yep, but that instead they jumped from some
[21:19] Speaker 2: other critter. Uh huh, oh boy, I'm going to guess raccoons.
[21:25] Speaker 2: You should have seen Kelly's face. What's wrong with guessing raccoons.
[21:29] Speaker 2: Raccoons have been part of human history for a long time, and.
[21:38] Speaker 1: I don't think I think raccoons are not like an
[21:41] Speaker 1: African or Asian species.
[21:43] Speaker 2: Okay, okay, I'm gonna guess. Give me another guests, give
[21:45] Speaker 2: me another guess. African or Asian species rats.
[21:50] Speaker 3: That's a good guess. But it's gorillas.
[21:52] Speaker 2: It's gorillas.
[21:53] Speaker 1: Okay, it's not a super distant ancestor, but it suggests
[21:56] Speaker 1: that that you know, we must have been having physical
[21:58] Speaker 1: contact with gorillas, and this is not going to be
[22:01] Speaker 1: that kind of show. The physical contact doesn't need to
[22:04] Speaker 1: have been like dirty contact. You can imagine that you
[22:08] Speaker 1: slaughtered a gorilla to eat it, and it was like
[22:10] Speaker 1: in your lap while you were butchering it or whatever.
[22:13] Speaker 1: But somehow we got close enough to them that their
[22:16] Speaker 1: lice jumped and took up habitation in our pubic region.
[22:20] Speaker 2: All right, First, orient me on gorillas and chimps and humans.
[22:24] Speaker 2: Humans and chimps split most recently six million years ago.
[22:28] Speaker 2: Gorillas are one split back or chimps include gorillas or
[22:31] Speaker 2: how does that work?
[22:32] Speaker 3: They're at least one split back.
[22:34] Speaker 1: We're all great apes, but they're like a few splits back.
[22:38] Speaker 2: Okay, So but the gorilla split is before the chimp split. Yes,
[22:42] Speaker 2: so you have gorilla lice and then chimp human lice,
[22:45] Speaker 2: and then chimp human lice split into chimp lice and
[22:47] Speaker 2: human lice. And now you're saying that the gorilla lice
[22:51] Speaker 2: contrary to what we were saying earlier about how lice
[22:53] Speaker 2: don't jump from species to species, this is one example
[22:56] Speaker 2: of when it did, and it somehow went from some
[22:59] Speaker 2: gorilla to somebody's pubic island.
[23:01] Speaker 1: Yes, right, so, so I mean sometimes you do you
[23:03] Speaker 1: get jumps and then that species specializes and so like,
[23:07] Speaker 1: you don't find human lice typically living on gorilla now
[23:11] Speaker 1: because they've become like, you know, pretty distinct separate species.
[23:14] Speaker 2: And so do we know when this jump happened? Like
[23:17] Speaker 2: it must have happened after humans and chimps split six
[23:21] Speaker 2: or seven million years.
[23:22] Speaker 1: Ago, right, Yes, so we think it happened about three
[23:25] Speaker 1: or four million years ago. As you mentioned, the split
[23:29] Speaker 1: with gorillas was even farther back than six million years
[23:33] Speaker 1: And so the fact that these lice jumped onto humans
[23:37] Speaker 1: three to four million years ago suggests that this is
[23:39] Speaker 1: not something where the lice were like following their ancestors
[23:43] Speaker 1: what they were doing over evolutionary time. This was just
[23:45] Speaker 1: like a jump that happened because gorillas and humans came
[23:48] Speaker 1: in physical contact. Their lice for some reason were able
[23:52] Speaker 1: to make the jump, and they were like, sweet, now
[23:54] Speaker 1: we're human lice.
[23:55] Speaker 2: Right. So I had two questions about that. One, Okay,
[23:57] Speaker 2: does that say something about the similarity between gorilla hair
[24:01] Speaker 2: and human pubic hair?
[24:02] Speaker 3: Hmm? I could.
[24:03] Speaker 2: And number two, how do we know this happened three
[24:05] Speaker 2: or four million years ago?
[24:07] Speaker 3: Okay? So one, I don't know.
[24:09] Speaker 1: Maybe maybe maybe gorilla hair is kind of like human pubic.
[24:13] Speaker 2: Hair, I'm gonna look at gorillas pretty differently from now on.
[24:17] Speaker 3: Well, maybe you should.
[24:19] Speaker 1: And the way that we time these things is you
[24:21] Speaker 1: can find certain genes in the human body that are
[24:25] Speaker 1: really important, so they shouldn't change much because if they change,
[24:29] Speaker 1: it could mess up something absolutely fundamental. Yeah, And then
[24:32] Speaker 1: you look at those genes in closely related species, and
[24:37] Speaker 1: based on the number of spots in the sequence where
[24:41] Speaker 1: there's differences, you can time how long they separated. So
[24:46] Speaker 1: if there's only one spot where they're different, they probably
[24:48] Speaker 1: didn't separate that long ago. But if there's like fifty
[24:51] Speaker 1: spots that are different than they probably separated a long
[24:54] Speaker 1: time ago. But it's not just long time ago. We
[24:58] Speaker 1: have what are called like molecular clocks, where essentially you
[25:01] Speaker 1: can look at the rate at which different genes tend
[25:04] Speaker 1: to pick up mutations and then back calculate how long
[25:07] Speaker 1: it must have been.
[25:08] Speaker 2: All right, So we look at gorilla lice and we
[25:10] Speaker 2: compare it to human pubic lice, and we see these
[25:13] Speaker 2: are pretty similar, and that's why we think this jump happened.
[25:17] Speaker 2: We also see there are differences, and by the number
[25:20] Speaker 2: of differences we can guess when this happened because we
[25:22] Speaker 2: know how long it takes to make these differences on
[25:25] Speaker 2: average beautiful.
[25:26] Speaker 3: Yeah, okay, that's right.
[25:27] Speaker 2: Wow, that's really fascinating. So we have head lice from
[25:31] Speaker 2: our common ancestor from chimps, and then pubic lice jumped
[25:34] Speaker 2: over three or four million years ago. And do we
[25:37] Speaker 2: think that before that the head lice were just not
[25:40] Speaker 2: in the pubic region because they were not adapted to it,
[25:43] Speaker 2: or were they all over the body and then they
[25:44] Speaker 2: got out competed in the pubic region. For those of
[25:47] Speaker 2: us who, like our common ancestors, are basically covered in hair,
[25:52] Speaker 2: do we have lice everywhere or is it only on
[25:54] Speaker 2: the head and in the pubic region? Like, does anybody
[25:56] Speaker 2: have back hair lice? As sexy as that sounds.
[26:00] Speaker 1: Oh yuh so okay, So body lice are lice that
[26:04] Speaker 1: tend to live in like your clothes, and so the
[26:06] Speaker 1: point is that there are lice that can be like
[26:09] Speaker 1: up against your back. But I think lice do well
[26:12] Speaker 1: in areas where the hair is very thick. Yeah, and well,
[26:16] Speaker 1: there are some of us who have a dense land bridge.
[26:21] Speaker 3: Between the head and the lower parts of our bodies.
[26:24] Speaker 2: I had a roommate from New Jersey once, who looked
[26:27] Speaker 2: like he was wearing a sweater when he didn't have
[26:28] Speaker 2: a shirt on.
[26:30] Speaker 3: I don't know if you had to specify the news
[26:32] Speaker 3: from New Jersey.
[26:34] Speaker 2: He liked saying New Jersey, only the strong survive, and
[26:37] Speaker 2: I just imagined it was a veritable jungle out there.
[26:40] Speaker 1: Okay, all right, Well, I think for the answers that
[26:44] Speaker 1: for most people, the hair and the rest of our
[26:45] Speaker 1: body is not as thick as the hair on our
[26:48] Speaker 1: heads are in our pubic region, and so you do
[26:51] Speaker 1: tend to have separation. But I don't know if head
[26:54] Speaker 1: lice were in the pubic region and then they were
[26:55] Speaker 1: out competed by lice that could hang on better.
[26:59] Speaker 3: Yeah, that's a great question. That's a great question. I
[27:03] Speaker 3: don't know who's spending their life on that one. But
[27:05] Speaker 3: I didn't find their papers.
[27:06] Speaker 2: Well here's another question, maybe you don't know the answer to, Okay,
[27:09] Speaker 2: is on the gorilla, is it the same lice all
[27:12] Speaker 2: over the body, or like human head lice jump over
[27:15] Speaker 2: to the gorilla pubic region or something crazy.
[27:17] Speaker 1: No, I think gorilla just have a species of lice
[27:20] Speaker 1: that you find all over their body. Okay, okay, And
[27:22] Speaker 1: so then there's this other thing that maybe you've heard.
[27:26] Speaker 1: I know I've heard it a couple of times, but
[27:28] Speaker 1: maybe it's not as common a misconception as I thought.
[27:30] Speaker 1: But I feel like every once in a while the
[27:33] Speaker 1: POPSI press will say pubic lice at risk of extinction
[27:37] Speaker 1: because of rise in bikini waxings.
[27:40] Speaker 3: Have you heard this?
[27:43] Speaker 2: I love it. Are Brazilians gonna put pubic lice out
[27:47] Speaker 2: of business? That's hilarious.
[27:49] Speaker 1: That's hilarious, And I think the answer is quite clearly no,
[27:51] Speaker 1: because it would have to be a global out. We
[27:55] Speaker 1: wouldn't exactly, we would all have to have Brazilians all
[27:58] Speaker 1: at once and make sure that all of our like
[28:01] Speaker 1: bed linens had been dried at like one hundred and
[28:03] Speaker 1: thirty degrees fahrenheit to kill all any pubic lice that
[28:06] Speaker 1: happened to be off. Although they don't live very long
[28:07] Speaker 1: off of the human body. But anyway, Yeah, I don't
[28:11] Speaker 1: think they're at risk of extinction.
[28:12] Speaker 3: I just really don't buy.
[28:13] Speaker 1: That, and I'm always amazed when it makes it in
[28:16] Speaker 1: the press. Again, I'm like, come on, man, it's not
[28:18] Speaker 1: like everyone is doing this.
[28:19] Speaker 2: Take them off the endangered species list. They can survive
[28:22] Speaker 2: on their own.
[28:23] Speaker 1: Yes, right, And I know that's like a big relief
[28:26] Speaker 1: for some people.
[28:26] Speaker 3: But okay, all right.
[28:28] Speaker 1: So now let's jump into body lice and head lice. Okay, okay,
[28:33] Speaker 1: So head lice and body lice have very different ways
[28:37] Speaker 1: that they go about their life. So head lice tend
[28:41] Speaker 1: to take lots of small meals, and they tend to
[28:44] Speaker 1: be smaller on average, and they just live in the
[28:47] Speaker 1: hair and they cling to the hairs. Body lice spend
[28:50] Speaker 1: a lot of their time living in the nooks and
[28:54] Speaker 1: crannies of your clothes, and they jump onto your body
[28:57] Speaker 1: to take a small number of bits big blood meals
[29:01] Speaker 1: a day, and they also tend to be bigger, and
[29:03] Speaker 1: then they retreat back into your clothes where they lay
[29:06] Speaker 1: their eggs.
[29:07] Speaker 2: All right, so body lice are different species from head.
[29:10] Speaker 3: Lice, we thought so.
[29:12] Speaker 1: Oh and so for a long time we thought body
[29:15] Speaker 1: lice and head lice are different, Like they look different,
[29:19] Speaker 1: they have different behaviors, and so we were like, okay,
[29:22] Speaker 1: they're different. And now here is another like story you
[29:24] Speaker 1: may have heard about lice because they're different. Dating that
[29:29] Speaker 1: divergence must tell you about when humans started to wear.
[29:33] Speaker 4: Clothes that would be cool.
[29:35] Speaker 3: That would be.
[29:36] Speaker 1: Cool, right, And so what we know from archaeological sites
[29:39] Speaker 1: is that something like seven hundred and.
[29:41] Speaker 3: Eighty thousand years ago we were scraping hides.
[29:45] Speaker 2: Seven hundred and eighty thousand years ago, we're talking almost
[29:48] Speaker 2: a million years ago. Yeah, yeah, people started preparing leather clothing.
[29:52] Speaker 1: Well, so almost a million years ago ancient humans were
[29:56] Speaker 1: scraping hides which could have been used as blankets. Maybe
[29:59] Speaker 1: they we weren't being used as clothes. We just know
[30:02] Speaker 1: they were scraping hides.
[30:03] Speaker 2: Maybe they were being used in bullfights or something, right, yeah.
[30:06] Speaker 1: Right, who the heck knows what they were being used for.
[30:07] Speaker 1: Maybe they were being they were umbrellas.
[30:10] Speaker 2: Maybe they had parades, that's real, pos right, and floats.
[30:14] Speaker 2: And I remember that humans have been using tools for
[30:17] Speaker 2: more than a million years, and so we're talking about
[30:19] Speaker 2: like stone tools here being scraped against the skin kind of.
[30:23] Speaker 1: Thing, probably, yes, all right, yeah, And then we have
[30:26] Speaker 1: evidence of eyed needles, so needles that you could put
[30:30] Speaker 1: it thread through from about forty thousand years ago.
[30:33] Speaker 2: That is mind blowing. Forty thousand year old eyed needles.
[30:37] Speaker 2: That's amazing.
[30:37] Speaker 3: Things so cool, right.
[30:38] Speaker 2: They're made out of bone or antler or something.
[30:41] Speaker 1: I don't know what they're made out of, but that
[30:43] Speaker 1: suggests that we were making pretty complicated clothes at that point.
[30:47] Speaker 1: We weren't just like cutting a hole and sticking our
[30:50] Speaker 1: arms through and it.
[30:51] Speaker 3: Was like toga style.
[30:52] Speaker 1: We were like, you know, doing something a little bit
[30:54] Speaker 1: fancier at that point. All right, yeah, okay, so that's
[30:58] Speaker 1: a pretty big gap. But we think that somewhere between
[31:02] Speaker 1: one point two and three million years ago is when
[31:04] Speaker 1: we started to lose our hair, and so, okay, so
[31:07] Speaker 1: then the question is can the split between body lice
[31:10] Speaker 1: and head lice tell us anything? Right? And so for
[31:13] Speaker 1: a while, this paper came out that was going all
[31:15] Speaker 1: over the place that said it looks like the split
[31:19] Speaker 1: happened about eighty three thousand to one hundred and seventy
[31:22] Speaker 1: thousand years.
[31:23] Speaker 2: Ago between body and head lice.
[31:25] Speaker 3: Between body and head lice, and so that could be
[31:27] Speaker 3: when we started wearing.
[31:28] Speaker 2: Clothes, because wearing clothes creates this new environment for body
[31:32] Speaker 2: lice to live their own.
[31:33] Speaker 3: Way, right, because now they can live in our clothes.
[31:35] Speaker 1: But okay, so I have seen this like set a
[31:39] Speaker 1: bunch of places, and I've probably repeated it, but we
[31:43] Speaker 1: don't think that these are separate species anymore. Maybe this
[31:46] Speaker 1: was a confusion looking at the different clades. So you know,
[31:49] Speaker 1: remember how we were talking about how we got body
[31:51] Speaker 1: lice from a lot of different places. But now we've
[31:53] Speaker 1: done experiments where if you let head lice get to
[31:57] Speaker 1: super high concentrations, some of them start to change their
[32:02] Speaker 1: body shape and move into clothes, and so it looks like, actually,
[32:07] Speaker 1: this is like a way that life's bodies respond to overcrowding.
[32:12] Speaker 1: They move into a different environment, and so it's not
[32:14] Speaker 1: different species. It's like an ecology. We'd call this phenotypic plasticity,
[32:19] Speaker 1: which is to say, something early in your environment tells you, hey,
[32:22] Speaker 1: you need to prepare for this kind of situation, and
[32:25] Speaker 1: bodies can go on like a different trajectory, like that's cool.
[32:28] Speaker 1: There are little aquatic organisms where if they can sense
[32:31] Speaker 1: that they're a fish in the area, they'll develop like
[32:33] Speaker 1: spikes on their heads and they can't get rid of
[32:36] Speaker 1: those spikes. They'll have those spikes for the rest of
[32:38] Speaker 1: their lives, but they're energetically expensive, so they only develop
[32:41] Speaker 1: them when they get cues early in life that like,
[32:43] Speaker 1: this is the kind of environment you live in.
[32:45] Speaker 2: So human head lice in the right situation, when the
[32:50] Speaker 2: head is already overcrowded, the babies will develop a different
[32:53] Speaker 2: form that's better suited to living in the clothing on
[32:56] Speaker 2: the body.
[32:56] Speaker 3: It does seem like that is what's happening.
[32:59] Speaker 2: And do chimp life do that also, or do we
[33:01] Speaker 2: think this is a feature human lice evolved because humans
[33:04] Speaker 2: were wearing clothing.
[33:05] Speaker 1: Yes, so I would not expect that chimp lice would
[33:08] Speaker 1: have something similar because they've got fur all over their bodies.
[33:11] Speaker 1: It's not like they have somewhere else to switch to.
[33:14] Speaker 1: And so I think we think that this is something
[33:17] Speaker 1: that has to do with like living in clothes.
[33:19] Speaker 2: And so if we could tell when human lice developed
[33:23] Speaker 2: this capability, then we could date when this environment became
[33:27] Speaker 2: available to the lice and learned about when the humans
[33:30] Speaker 2: started wearing clothing. But that doesn't seem possible. Is that possible, right?
[33:34] Speaker 1: I wouldn't know how to start there, I mean, because
[33:37] Speaker 1: they're all interbreeding, right, And so I mean, I think
[33:41] Speaker 1: what's happening is that they are using genes that they
[33:44] Speaker 1: already have and they are just expressing them differently. You
[33:47] Speaker 1: could maybe date it if this ability came from some
[33:53] Speaker 1: like gene that got added to the population, and you
[33:55] Speaker 1: could try to time when that gene got in there,
[33:57] Speaker 1: but as far as I know, yeah, you really can't
[34:00] Speaker 1: time this. And this is just like so now we
[34:02] Speaker 1: call them two different kinds of eco morphs. And I
[34:05] Speaker 1: want to be clear, we really don't understand what's happening
[34:08] Speaker 1: here very well, but we no longer think of them
[34:10] Speaker 1: as separate species. It looks like head lice can become
[34:13] Speaker 1: body lice and they're interbreeding.
[34:15] Speaker 2: Interesting, all right, And so then head lice really are
[34:20] Speaker 2: whole body lice except for the pubic region.
[34:23] Speaker 1: Yeah, yeah, except they sow your kids. You take them
[34:28] Speaker 1: to I was gonna say lice upon a time. I
[34:31] Speaker 1: cannot remember. Once upon a life time. That's not what
[34:36] Speaker 1: it's called, is it once in a lifetime? Okay, right,
[34:41] Speaker 1: So you took your kids immediately to once in a lifetime,
[34:44] Speaker 1: which means the density of head lice didn't get very high,
[34:49] Speaker 1: and so they didn't jump to place. And so in
[34:52] Speaker 1: the United States, you know, children of wealthy families like
[34:56] Speaker 1: our children, the lice doesn't get that. But if you
[35:02] Speaker 1: are someone who's unhoused and doesn't have the opportunity to
[35:05] Speaker 1: change or wash their clothes for long periods of time,
[35:08] Speaker 1: or shower for long periods of time. It can build
[35:11] Speaker 1: up and then body lice become a problem. But what
[35:15] Speaker 1: has really become a problem is body lice during periods
[35:19] Speaker 1: in our history where we have had concentration camps or
[35:23] Speaker 1: war and in those situations you get a lot of
[35:26] Speaker 1: body lice. And one of the things that differentiates body
[35:30] Speaker 1: lice from head lice is how their immune system responds
[35:34] Speaker 1: to pathogens. Oh so when we get back, we're going
[35:37] Speaker 1: to talk about how body lice have killed millions of
[35:40] Speaker 1: people throughout history, whereas head lice pretty much don't.
[35:45] Speaker 2: Wow fascinating. All right, let's take a break. When we
[35:47] Speaker 2: come back, we'll hear all about the lice wars.
[35:50] Speaker 1: And we're back, and we've talked about how head lice
[36:14] Speaker 1: and body lice are very closely related. And our best
[36:16] Speaker 1: guess at the moment is that body lice are just
[36:20] Speaker 1: head lice that in a high competition environment, have sort
[36:23] Speaker 1: of changed the way their body is shaped and now
[36:26] Speaker 1: they're living in your clothes.
[36:28] Speaker 2: And so here Kelly is nitpicking the science for all
[36:31] Speaker 2: of you.
[36:32] Speaker 1: That's right, that's right, And again I want to clarify
[36:34] Speaker 1: it there's a lot that we don't know. This is
[36:36] Speaker 1: like the story literally, as I've been reading like every
[36:39] Speaker 1: five or ten years worth of like literature chunks, they've
[36:41] Speaker 1: been like, oh, we've kind of changed our mind about this,
[36:43] Speaker 1: and so this is an evolving story.
[36:46] Speaker 3: But part of why we think that body.
[36:48] Speaker 1: Lice can transmit disease is that one of the things
[36:50] Speaker 1: that differs between head and body lice is how they
[36:53] Speaker 1: respond when they get infected with a pathogen and the
[36:57] Speaker 1: volume of their blood meals changes. So a disease that's
[37:02] Speaker 1: transmitted by body lice that has been absolutely horrible for
[37:05] Speaker 1: humans in the past is called epidemic typhus.
[37:09] Speaker 2: Sounds bad.
[37:10] Speaker 3: I hate the word typhus.
[37:12] Speaker 1: Because there are three different kinds of typhises. They're all
[37:17] Speaker 1: very different, and it's different than typhoid fever. So just
[37:22] Speaker 1: keep in mind that there's a lot of other things
[37:24] Speaker 1: that you might have heard about that are not the
[37:26] Speaker 1: thing we're about to talk about right now, But epidemic
[37:29] Speaker 1: typhus is what we're talking about, and it is caused
[37:31] Speaker 1: by a bacteria called Ricketsia prawazechii. And Daniel's like, why
[37:36] Speaker 1: did you have to say the scientific name?
[37:37] Speaker 3: And Daniel.
[37:38] Speaker 1: I had to say the scientific name, because that is
[37:40] Speaker 1: the way you can be sure that you are talking
[37:42] Speaker 1: about the disease that I'm about to tell you about.
[37:45] Speaker 2: Look, I've succeeded. I don't even need to make my
[37:47] Speaker 2: objection anymore. It's already in your brain. And now I
[37:51] Speaker 2: just have you questioning yourself, which is good because this
[37:53] Speaker 2: means you only give us the Latin name when we
[37:56] Speaker 2: actually need it, so I can retire.
[38:00] Speaker 1: Well, I look forward to when you stop telling us
[38:02] Speaker 1: about all the different particles and you call it a
[38:03] Speaker 1: particle one, two, and three.
[38:05] Speaker 3: But anyway, all right, all.
[38:06] Speaker 2: Right, So what does this bacterium do?
[38:08] Speaker 1: So this is a nasty bacteria. So the lice get
[38:10] Speaker 1: infected by taking a blood meal from a human who
[38:13] Speaker 1: already has the bacteria in their body. Okay, the bacteria
[38:17] Speaker 1: replicates inside of the lice and eventually is going to
[38:21] Speaker 1: kill the lice also.
[38:23] Speaker 3: And so when we.
[38:24] Speaker 1: Talk about malaria, we talk about how the mosquito gives
[38:27] Speaker 1: it to people when they bite you, and it essentially
[38:30] Speaker 1: like comes out in the saliva into our body. That's
[38:33] Speaker 1: not what happens here. What happens here is that the
[38:35] Speaker 1: lice poop on your body or die on your body. Oh,
[38:39] Speaker 1: and all of those bites are itchy. So you scratch,
[38:42] Speaker 1: and when you scratch, you scratch the bacteria which is
[38:46] Speaker 1: still present in the poop and the body parts of
[38:48] Speaker 1: the lice. You scratch that into your body, or maybe
[38:51] Speaker 1: you get it on your hands, and then you rub
[38:53] Speaker 1: your eyes and it gets in through the mucous membranes.
[38:55] Speaker 2: This is if I don't have the bacterium in my
[38:58] Speaker 2: blood yet, but I've gotten a house from somebody who
[39:01] Speaker 2: does have it, that it can cross back into my
[39:04] Speaker 2: body through an I've scratched.
[39:06] Speaker 3: Yeah, exactly right.
[39:07] Speaker 1: So if you borrow the coat of somebody who has
[39:10] Speaker 1: lice and they gave their lice epidemic typhus, and then
[39:14] Speaker 1: that lice dies on you or poops on you and
[39:16] Speaker 1: you scratch, now you've got it.
[39:17] Speaker 2: Oh boy.
[39:18] Speaker 1: And so what it does is it lives in the
[39:21] Speaker 1: cells that line your blood vessels, and in particular, it
[39:24] Speaker 1: tends to line the blood vessels when they get really thin,
[39:27] Speaker 1: and this includes the blood vessels in your brain. So
[39:31] Speaker 1: the root for typhus is a Greek word. I think
[39:34] Speaker 1: that means hazy or foggy, and that refers to the
[39:38] Speaker 1: fact that it has a lot of neurological symptoms that
[39:41] Speaker 1: make I know, I know it's the worst. And so
[39:44] Speaker 1: what it's doing is it like it's living in your
[39:46] Speaker 1: blood vessels, including the ones in your brain, and it
[39:49] Speaker 1: replicates and replicates and replicates until it bursts open those
[39:52] Speaker 1: blood vessels. And now you've got these leaky blood vessels.
[39:56] Speaker 4: That sounds bad, super bad.
[39:58] Speaker 1: And then your body responds trying to clot and stop
[40:02] Speaker 1: that leaking. And so now you've also got blood clots
[40:05] Speaker 1: in your brain or in these other parts of your body.
[40:08] Speaker 1: And so there tend to be a lot of neurological symptoms.
[40:10] Speaker 1: In the past, this parasite was associated with death rates
[40:14] Speaker 1: up to sixty percent. If you survived, that was great,
[40:18] Speaker 1: but a lot of people you know, would not survive it.
[40:20] Speaker 2: Wow, And so have there been big outbreaks of this?
[40:24] Speaker 2: Is this why it's called epidemic?
[40:25] Speaker 4: Yes? Yes, you shouldn't say yes.
[40:28] Speaker 2: So enthusiastically, Kelly, we're talking with a lot of suffering here.
[40:33] Speaker 2: Why am I laughing?
[40:34] Speaker 1: I'm not right, yeah right, I'm not excited about the suffering.
[40:37] Speaker 1: I'm interested in the fact that pretty much none of
[40:40] Speaker 1: us have heard of epidemic typhus, because this is like
[40:45] Speaker 1: a problem that doesn't bother most of us in our.
[40:47] Speaker 3: Day to day lives anymore.
[40:48] Speaker 2: Yay, yay.
[40:49] Speaker 1: But for example, during World War One, the Bolshevik Revolution happened,
[40:54] Speaker 1: and so Lenin and the rest of his Bolsheviks were
[40:58] Speaker 1: essentially starting a civil or within Russia. They didn't want
[41:02] Speaker 1: to be part of World War One anymore, so they
[41:03] Speaker 1: tried to pull out. The Germans sort of kept coming anyway,
[41:07] Speaker 1: and so you had this civil war happening in Russia
[41:10] Speaker 1: at the same time as World War One, and things
[41:13] Speaker 1: were just an absolute disaster. Epidemic typhus started sweeping through.
[41:16] Speaker 1: People couldn't like wash their clothes or shower regularly enough,
[41:20] Speaker 1: and something like twenty to thirty million people got infected
[41:24] Speaker 1: by epidemic typhus, and like two to three million people died,
[41:27] Speaker 1: oh man, right during World War One, So that was
[41:31] Speaker 1: obviously not good. Another thing that's kind of a bummer
[41:34] Speaker 1: from the perspective of humans having this disease is that
[41:37] Speaker 1: it seems to be able to like live sort of
[41:40] Speaker 1: quietly in our body for a long time, so you
[41:43] Speaker 1: can be fine, and then something stressful happens, and now
[41:48] Speaker 1: you have a less intense version of epidemic typhus, but
[41:51] Speaker 1: you have epidemic typhus again. It used to be called
[41:54] Speaker 1: I think breathement syndrome because this would like people who
[41:57] Speaker 1: would be absolutely stressed out in devas dated because someone
[42:00] Speaker 1: they love died would end up having epidemic typhus essentially
[42:04] Speaker 1: wake back up again and make them feel miserable all
[42:07] Speaker 1: over again.
[42:08] Speaker 2: What's the connection between stress and the disease waking up?
[42:10] Speaker 3: Ah?
[42:11] Speaker 1: So like uh diseases, even like shingles. So shingles is
[42:14] Speaker 1: when the chicken pox virus wakes back up again, which
[42:17] Speaker 1: is really bad, right, Yeah, Oh my gosh. Zach had
[42:19] Speaker 1: it and he felt like he was having a heart attack.
[42:21] Speaker 1: It was absolutely horrible. And so there are viruses and
[42:24] Speaker 1: bacteria that can infect you when you're young, and then
[42:27] Speaker 1: years later when you get super stressed out that can
[42:30] Speaker 1: suppress your immune system. And when your immune system is suppressed,
[42:33] Speaker 1: these organisms i'd wake back up again is a very
[42:37] Speaker 1: anthropomorphic way of saying it. But they take advantage of
[42:39] Speaker 1: your immune systems weak in state to essentially give you
[42:42] Speaker 1: the disease all over again, or a slightly different version
[42:45] Speaker 1: of the disgus. So shingles is like the adult version
[42:48] Speaker 1: of chicken pox.
[42:49] Speaker 2: And that's for people who had chicken pox as a kid. Right,
[42:51] Speaker 2: So chicken pox parties bad idea.
[42:54] Speaker 3: Well, yeah, right, bad idea.
[42:56] Speaker 1: Vaccinations for chicken pox, great idea. I don't expect that
[43:00] Speaker 1: my children are ever going to have to suffer through
[43:02] Speaker 1: shingles like my husband did, or like I might have to.
[43:05] Speaker 3: Who knows what awaits in the future.
[43:07] Speaker 2: Yay chicken pox roulette. So in this case, we're talking
[43:12] Speaker 2: about a disease that's in your blood can lay dormant,
[43:15] Speaker 2: but then when you get stressed out or you have
[43:17] Speaker 2: a terrible life event, it can rear its ugly head.
[43:20] Speaker 2: That's terrible, take advantage of you when you're down.
[43:22] Speaker 3: Totally terrible, totally terrible.
[43:24] Speaker 1: But you know, for most of us in the United States,
[43:26] Speaker 1: we haven't been exposed to epidemic typhus. We haven't been
[43:30] Speaker 1: in like war or refugee situations, because we're very lucky
[43:34] Speaker 1: in that regard.
[43:35] Speaker 2: But why is that exactly? Is that because we just
[43:37] Speaker 2: don't have very many lice, or because the lice we
[43:40] Speaker 2: do have are not infected or both both.
[43:43] Speaker 1: So the big thing is that your head lice don't
[43:47] Speaker 1: become body lice unless you are not showering or washing
[43:51] Speaker 1: your clothes regularly, right, And that happens more often in
[43:54] Speaker 1: situations where you're a refugee, or you're.
[43:58] Speaker 3: Unhomed, or it's a war.
[44:01] Speaker 2: Got it.
[44:01] Speaker 1: So, for example, lice diseases, this one and others, including
[44:06] Speaker 1: one called trench fever, was a really big problem in
[44:09] Speaker 1: World War One when they were in the trenches and
[44:12] Speaker 1: they couldn't get out to shower regularly, and so the
[44:16] Speaker 1: lice built up to very high numbers. The head lice
[44:18] Speaker 1: became body lice, and now they're transmitting disease and you're
[44:22] Speaker 1: in close quarters, so it's jumping from one person to another.
[44:25] Speaker 2: Got it, I see.
[44:26] Speaker 1: But in the United States there's a reservoir for the
[44:30] Speaker 1: bacteria which I won't say again so that Daniel doesn't
[44:33] Speaker 1: get upset with me. And the reservoir are little flying squirrels.
[44:38] Speaker 1: What Yeah, So people who interact with flying squirrels or
[44:42] Speaker 1: their nests where the lice can get left behind for
[44:45] Speaker 1: a little while, are some of the rare cases of
[44:48] Speaker 1: epidemic typhus that you see in the United States.
[44:50] Speaker 2: And when you say reservoir, you don't mean like a
[44:52] Speaker 2: lake out there with water we can drink. You mean,
[44:55] Speaker 2: someplace where the disease is like hiding out and hanging
[44:58] Speaker 2: out and waiting to.
[44:59] Speaker 1: Stry quite so, yes, that's right, that's right. So for
[45:03] Speaker 1: the most part, we don't worry about epidemic typhus. If
[45:05] Speaker 1: somebody does happen to get epidemic typhus, you can treat
[45:08] Speaker 1: it with doxycycline, which is an antibiotic.
[45:10] Speaker 2: Thank you, Big Pharma.
[45:11] Speaker 3: That's right. Yeah.
[45:12] Speaker 1: Yeah, So being in the United States is pretty great
[45:15] Speaker 1: when you are able to regularly shower and wash your clothes.
[45:19] Speaker 1: Hans Zinzer, who's like famous for writing Rats, Lice and History,
[45:22] Speaker 1: which is like a book on epidemic typhus.
[45:25] Speaker 2: I've been itching to read that book.
[45:26] Speaker 3: Ah.
[45:27] Speaker 1: I honestly, I don't recommend it. I like he goes
[45:30] Speaker 1: on long tirades about like art and science and they're
[45:33] Speaker 1: not particularly insightful, and like, oh wow, you gotta get
[45:37] Speaker 1: at least like twenty five percent of the way through
[45:39] Speaker 1: the book before he starts talking about typhus, and you're like,
[45:41] Speaker 1: get to the point, and he starts each chapter with
[45:43] Speaker 1: I'm sorry about the digression, and you're like, you should
[45:46] Speaker 1: be get to Typhus.
[45:48] Speaker 2: Sounds like the book needed an editor, I know.
[45:50] Speaker 1: Right, And so anyway, he has this great quote, Typhus
[45:53] Speaker 1: will continue to break into the open whenever human stupidity
[45:56] Speaker 1: and brutality give it a chance. So anyway it happens
[45:59] Speaker 1: to come a long with war and refugee situations.
[46:03] Speaker 2: That is a pretty great quote.
[46:04] Speaker 3: That is a pretty great quote. He does. He's got
[46:06] Speaker 3: a lot of great quotes in the book.
[46:08] Speaker 1: Got He's got another quote about how you should feel
[46:10] Speaker 1: bad because the lice give up their little ghost when
[46:14] Speaker 1: they die from Typhus, and so maybe you should like
[46:17] Speaker 1: not feel so bad about the lice.
[46:19] Speaker 3: And if anybody wants a lot more detail on.
[46:21] Speaker 1: These diseases, they should check out the Typhus episode on
[46:25] Speaker 1: this podcast will Kill You Anyway. Lots of additional great
[46:28] Speaker 1: quotes in that podcast.
[46:29] Speaker 2: I didn't mean to brush off the suffering of the lice.
[46:32] Speaker 3: Uh, yeah, that's right. I don't feel as bad for
[46:35] Speaker 3: lice as I do for people.
[46:36] Speaker 1: Okay, anyway, there's also lous born relapsing fever. This is
[46:40] Speaker 1: caused by a different kind of bacteria. It gives you
[46:42] Speaker 1: fevers that kind of come and go. There's estimates that
[46:45] Speaker 1: around World War One, about five million people died from
[46:49] Speaker 1: this fever as well. And this was happening like in
[46:52] Speaker 1: the trenches and stuff. And then there's trench fever, which
[46:55] Speaker 1: we talked about a little bit earlier, which was a
[46:57] Speaker 1: problem for the people living in trenches. But it's still
[47:00] Speaker 1: problem now in some parts of the world where lice
[47:04] Speaker 1: can kind of reach high numbers. But so we talked
[47:07] Speaker 1: about how, you know, millions of people died during World
[47:09] Speaker 1: War One from diseases transmitted by lice. There's another figure
[47:14] Speaker 1: that goes around a lot when you're you know, reading
[47:16] Speaker 1: through the Lyces literature, as some of us do, And
[47:20] Speaker 1: there is a cemetery where some of Napoleon's soldiers from
[47:25] Speaker 1: the Grand Army were buried, and this was after they
[47:29] Speaker 1: went to Moscow and were you know, defeated by the
[47:32] Speaker 1: Russian winter, and about a third of the dental pulpe
[47:37] Speaker 1: that they went through. So sometimes you can find like
[47:39] Speaker 1: evidence of bacterial infections in dental pulp in skeletons, about
[47:43] Speaker 1: a third of them.
[47:44] Speaker 2: Sorry, dental pulp. This is like the inner part of
[47:47] Speaker 2: a tooth or something.
[47:48] Speaker 1: Yeah, yeah, the inner part of the tooth. If you
[47:50] Speaker 1: can like extract that and do like genetic sequencing on it,
[47:53] Speaker 1: which they were able to.
[47:55] Speaker 2: They dug up all these graves.
[47:57] Speaker 3: Yeah, they dug up all these grapes.
[47:58] Speaker 1: I mean, this kind of stuff happens a lot for
[48:01] Speaker 1: historic when you're trying to study history. But anyway, they
[48:04] Speaker 1: found that a third of the soldiers that were in
[48:06] Speaker 1: those graves were carrying diseases transmitted by lice, and so
[48:11] Speaker 1: it looks like lice might have played a role in
[48:13] Speaker 1: defeating Napoleon's army in addition to the horrible Russian winters.
[48:17] Speaker 2: Wow, amazing.
[48:18] Speaker 1: Yeah, But like, just to really emphasize how many people
[48:21] Speaker 1: died there, Napoleon went to Moscow with half a million
[48:26] Speaker 1: people came back. Do you want to guess how many
[48:28] Speaker 1: he came back with.
[48:29] Speaker 2: Let's see, twenty percent died from lice. So I'm gonna
[48:34] Speaker 2: go on, maybe one hundred.
[48:35] Speaker 1: Thousand, three thousand, three thousand, three thousand.
[48:39] Speaker 2: Don't sounds so exciting, Kelly. You're talking about human death here, right, okay,
[48:46] Speaker 2: three thousand. Now it sounds like you're pretending to care. Well, okay,
[48:51] Speaker 2: I care, but like it's dramatic, Yeah, I agree, Yes.
[48:54] Speaker 1: My voice is trying to convey like just the like
[48:57] Speaker 1: mind blowingness of like, holy cow.
[48:59] Speaker 3: That is so many. This is like what was Napoleon
[49:02] Speaker 3: doing anyway? History? Okay, so let's wrap things up.
[49:06] Speaker 1: There have been a lot of different instances throughout history
[49:08] Speaker 1: where lice transmitted diseases have killed millions of humans. Yeh,
[49:13] Speaker 1: lucky for us today, especially if you live in a
[49:16] Speaker 1: place like the United States. When you get lice, which
[49:19] Speaker 1: happens to six to twelve million kids every year. Wow,
[49:23] Speaker 1: what you think is, ah, I have to go to
[49:25] Speaker 1: once in a life's time again, you don't think, I
[49:28] Speaker 1: hope I don't get epidemic typhus.
[49:30] Speaker 2: But now I'm gonna think that.
[49:32] Speaker 1: Okay, well, your kids are old enough that hopefully they're
[49:35] Speaker 1: not bringing home head lice anymore.
[49:36] Speaker 2: No, no longer.
[49:38] Speaker 1: Yeah, yeah, and so so now we treat this with
[49:40] Speaker 1: like you know, with combs and specialized shampoos. There's an
[49:44] Speaker 1: interesting new treatment that people are trying out. So lice
[49:47] Speaker 1: have an endosymbiotic bacteria, so a bacteria that lives inside
[49:51] Speaker 1: of them, and that bacteria is critical for providing the
[49:55] Speaker 1: lice with B vitamins, which are not present in human blood.
[49:59] Speaker 1: And so people are trying to explore whether or not
[50:01] Speaker 1: you can use antibiotics to kill the bacteria that live
[50:05] Speaker 1: inside of the lice, and if that will then kill
[50:08] Speaker 1: the lice because they need those bacteria, or the lice just.
[50:11] Speaker 2: Get like the Lyce's version of scurvy or something.
[50:14] Speaker 3: Yeah. H this be a bad head, all right, all right, all.
[50:23] Speaker 2: Right, Well this is a fascinating dive into history. It
[50:26] Speaker 2: is tragic, of course that lice terrorize people and kill
[50:29] Speaker 2: so many people, but it's also fascinating that it can
[50:32] Speaker 2: tell us so much about our ancient ancient.
[50:35] Speaker 1: History, or that it can confirm what we already think
[50:38] Speaker 1: is happening with our ancient ancient history. As I said,
[50:41] Speaker 1: I have to be a wet blanket. But still there's
[50:43] Speaker 1: lots of interesting stuff going on here. So yes, more
[50:45] Speaker 1: money to study lice.
[50:46] Speaker 2: But they do tell us about this gorilla human crossover event. Yeah, yeah,
[50:51] Speaker 2: that we didn't know about before.
[50:52] Speaker 1: I mean, I guess you, like, how interesting is it
[50:55] Speaker 1: to know that humans interacted with gorillas in the past,
[50:58] Speaker 1: Like I would have guessed that we were killed and
[51:00] Speaker 1: eating gorillas.
[51:01] Speaker 3: You kill and eat whatever you need to when you're
[51:04] Speaker 3: an ancient human.
[51:05] Speaker 2: I don't know Kelly's ancestors killed and eight gorillas.
[51:07] Speaker 3: All the time.
[51:08] Speaker 2: It sounds come on down for a gorilla barbecue at
[51:11] Speaker 2: Kelly's ancestors house.
[51:12] Speaker 1: That's right, okay, all right, well you're all invited.
[51:16] Speaker 2: Did you say you grew up in New Jersey? Not surprised.
[51:19] Speaker 1: All my ancestors are largely I guess French and Irish,
[51:25] Speaker 1: and so you know, a bunch of us might have died,
[51:28] Speaker 1: you know, hiking back from Moscow with Napoleon's grand or
[51:31] Speaker 1: may or whatever. And then during the Great Irish Famine,
[51:35] Speaker 1: the Potato famine around like eighteen forty five eighteen forty eight,
[51:38] Speaker 1: there was also a lot of deaths because of disease
[51:42] Speaker 1: at that time, Like if you are starving, you probably
[51:44] Speaker 1: don't have the energy to change your clothes or shower.
[51:46] Speaker 3: So epidemic Typhus killed a bunch of Irish people there
[51:49] Speaker 3: as well.
[51:49] Speaker 1: So ancestors on both sides of my family were dying
[51:53] Speaker 1: from Typhus.
[51:55] Speaker 2: Maybe, she said, gleefully.
[51:58] Speaker 1: This is just the tone of voice at which I
[52:00] Speaker 1: approach everything in my life.
[52:02] Speaker 2: I might consider having different toes or different topics, you know,
[52:06] Speaker 2: all right, Or folks out there who want a really
[52:08] Speaker 2: bright eulogy write to Kelly, she will come to your
[52:11] Speaker 2: funeral and talk gleefully about your death.
[52:13] Speaker 1: Yes, if your funeral is a celebration of life, then
[52:16] Speaker 1: invite me. If it is a celebration of lice, Oh
[52:21] Speaker 1: all right, we need to we need to knock this off.
[52:23] Speaker 1: It's time for us to go.
[52:24] Speaker 2: Thanks everybody for taking this journey with us.
[52:27] Speaker 3: Until next time.
[52:34] Speaker 2: Thanks everybody for listening. Please go and do us a
[52:37] Speaker 2: favor and rate the show on whatever podcast app you're using.
[52:40] Speaker 2: It really helps people find us.
[52:42] Speaker 1: Daniel and Kelly's Extraordinary Universe is edited by the amazing
[52:46] Speaker 1: Matt Kesselman.
[52:47] Speaker 2: He really is a wizard. You can also find us
[52:50] Speaker 2: online on Blue Sky, Instagram, and x D and K Universe.
[52:55] Speaker 2: Come engage with us.
[52:57] Speaker 1: You can email us I had questions at Daniel and Kelly.
[53:00] Speaker 1: We really do want to hear.
[53:02] Speaker 2: From you, and you can find our website www dot
[53:05] Speaker 2: danieland Kelly dot org, where you'll also find an invitation
[53:09] Speaker 2: to join our discord where everybody comes and talks about
[53:12] Speaker 2: the amazing.
[53:13] Speaker 1: Universe, and we also have the most amazing moderators. This
[53:17] Speaker 1: is an iHeart podcast. Thanks for joining us.

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