Ecomorphological and Ecometric Approaches to Clarifying Homo sapiens Palaeoecology

Currently, fossil, archaeological, and genetic evidence suggest that the origins of Homo sapiens lie somewhere in Africa during the late-Early to Middle Pleistocene period (~1,000,000-500,000 years ago). The morphological diversity of hominin fossils, the patterns seen in technological and cultural evolution, and the signals of genetic exchanges from this time period are puzzling and are yet to be fully understood. Hominin evolution, whether biological or cultural, is naturally connected to ecological, environmental, and climatic changes. Thus, reconstructing the ecology of Homo sapiens origins and interpreting the influence of ecological dynamics on the subsequent evolution of our species are crucial areas of research. These broad research questions establish the backdrop for the objectives of this thesis. This thesis reports on the application of established and novel palaeoecological methods - bovid astragalus ecomorphology and dental ecometrics - to bring new and added perspectives on the ecological and environmental context in which Homo sapiens and other hominin relatives evolved. Ecomorphology is initially used to create models capable of predicting habitat preferences of fossil bovids. This is accomplished by fitting the models on a large dataset of morphological variables collected on modern bovid astragali from the National Museum of Kenya, the Cambridge University Museum of Zoology, and the Muséum National d’Histoire Naturelle in Paris. The models created using the modern data are 2.1-3.2x better than chance at predicting habitat types assigned to the specimens in the modern dataset. These models are further validated using an astragalus sample from African Humid Period (AHP) (~14,800-5,500 years ago) sites of the Turkana region. In doing so, this thesis also works towards providing a more complete picture of the unique ecology of the Turkana Basin during the African Humid Period. Building upon these analyses, the modern ecomorphological models are applied to fossil astragali recovered from late-Early Pleistocene (LEP) (~1,500,000-781,000 years ago) and Middle Pleistocene (MP) (781,000-126,000 years ago) palaeontological localities in Kenya. Following the ecomorphological analyses, dental ecometrics of large mammalian herbivores are used to predict mean annual temperature (MAT), mean annual precipitation (MAP), and net primary productivity (NPP) of 48 late-Early Pleistocene, Middle Pleistocene, and early-Late Pleistocene (ELP) faunal assemblages across Northern, Eastern, and Southern Africa. The results of the ecomorphological and ecometric analyses presented in this thesis have methodological implications, and implications for our interpretation of hominin palaeoecology and biogeography during the LEP, MP, and ELP periods. While both ecomorphology and ecometrics are validated as valuable and informative palaeoecological methods, some limitations are identified, and methodological refinements are proposed. Finally, the ecological and climatic predictions produced by the ecomorphological and ecometric analyses are discussed alongside and compared to findings produced by other palaeoecological methods, offering fresh insights into the palaeoecology of Homo sapiens.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2025

Author dc:creator

• Van Schalkwyk, Matthew

Advisor dc:contributor.advisor

• Mirazón Lahr, Marta

• palaeoanthropology
• palaeoecology
• ecomorphology
• ecometrics
• human evolution
• archaeology

Licence

• https://www.repository.cam.ac.uk/bitstreams/f1328e5f-de3c-45be-89f2-207719abf556/download
• http://purl.org/NET/rdflicense/allrightsreserved

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.123942

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/393741