9.2: Early Homo Lab

Learning Objectives

• Examine cranial and postcranial differences among Australopithecus africanus, Homo habilis, and Homo erectus
• Compare and contrast the logics of “lumping” and “splitting”
• Describe variation within Homo erectus
• Identify early Homo tool traditions

Introduction

In this lab students examine fossils of the earliest species of the genus Homo: Homo habilis and Homo erectus. Both species overlap with the end of the Australopithecines chronologically, with Homo erectus outliving any of the rest. Debate surrounds the classification of both species, primarily about whether they should be lumped into one species each, or split into two. For example, all Homo habilis could be lumped as Homo habilis, or split into Homo habilis and Homo rudolfensis.

By approximately 2.5 million years ago (mya), the earliest members of the genus Homo (Homo habilis) had developed, and by 1.6 mya Homo erectus had spread throughout Africa and Asia. To understand the big picture - the key changes with the advent and spread of early Homo - students will examine and record the differences between Australopithecus africanus, Homo habilis, and Homo erectus.

In this activity students utilize links to 3D models of several hominin species and early hominin tools to make observations about and compare them. Students will then complete data tables and answer questions about these models.

Steps

1. Trends of the Genus Homo: Examine 3D scans of fossils from different Homo species; complete the chart and answer questions on the worksheet to identify major trends across the genus.
2. Lumping and Splitting: Homo habilis v. Homo rudolfensis: Compare the type specimens for Homo habilis and (possible) Homo rudolfensis; complete the chart and answer questions.
3. Homo erectus Over Space and Time: Examine Homo erectus fossils from four different sites; complete the chart and answer questions.
4. Changing Postcrania: Compare postcrania features of Au. afarensis, H. habilis, H. erectus, and H. sapiens.
5. Developing Tools: Record observations about Lomekwian, Oldowan, and Acheulean tool traditions.

References

efossils. 2021. 3D fossils from efossils.org at the University of Texas at Austin.

eskeletons. 2021. 3D fossils. eskeletons.org at the University of Texas at Austin.

Sketch Fab. 2021. 3D fossils from sketchfab.org.

Yoshida-Levine, Bonnie. 2019. “Chapter 10: Early Homo.” In Explorations: An Open Invitation to Biological Anthropology, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. Arlington, VA: American Anthropological Association.

Image Attributions

Figure 1. KNM-WT 15000 Turkana Boy Skeleton by Smithsonian [exhibit: Human Evolution Evidence, Human Fossils, Fossils, KNM-WT 15000] is copyrighted and used for educational and non-commercial purposes as outlined by the Smithsonian.

Figure 2. Homo erectus site map original to Explorations: An Open Invitation to Biological Anthropology by Chelsea Barron at GeoPlace, California State University, Chico is under a CC BY-NC 4.0 License.

Early Homo Lab Worksheet

In the table below, each species’ name contains links to 3D scans of fossils from Sketchfab. If possible, you are encouraged to open two or more of these links at the same time (in different windows) to allow you to look at them at the same time and compare them. You can record your observations using comparative terms such as “largest”, “smallest”, “most prognathic”, in addition to specific descriptive terms like “parabolic” or “U-shaped” that were presented in the chapter.

Based on your observations, what are two major trends that continue across the genus Homo?

The genus Homo suggests reliance on tools as well as dietary and behavioral flexibility. The earliest fossils that belong to this genus appear between 2.8 and 2.5 mya, and they extend to about 1.7 mya. This fossil collection, however, does vary significantly in facial and cranial size, suggesting to some they should be “split” into two separate species. Other paleontologists prefer to “lump” similar fossils explaining the diversity as natural variation or differences between the sexes.

Compare the type specimens for Homo habilis and (possible) Homo rudolfensis. What differences do you observe? Given what you saw for species differences in previous fossil comparisons, do you think there are enough differences to consider them two different species?

Consider other features: what similarities do you see between the two fossils?

Based on your observations, do you think that H. habilis should be one species or split into two? Why or why not?