Revisiting Homo Taxonomy: A Geometric Morphometric Analysis of the Hominin Skeleton

Kenyon, Brittany, Winston Salem NC

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2020, Research Using Biological Collections. The fellowship supports research and training of the Fellow that will utilize biological collections in innovative ways. Humans belong to the incredibly diverse and geographically widespread genus Homo. The wide range of diversity seen in the skeletons of humans and their ancestors (hominins) makes it difficult to scientifically classify them – do hominins belong to one incredibly diverse species or to several different species? Historically, the shape and features of a skeletal fossil are used to help identify what species it belongs to, though these classifications ignore the fact that the wide range of diversity should cause us to rethink how we define a species. This project investigates the extent to which the range of variation seen in human ancestors mimics that of another group of geographically widespread primates, macaque monkeys. This research advances scientific knowledge by allowing for more accurate classification methods that will allow us to better understand ourselves and our ancestors, and how we are related. The 3D models generated during the project will be published online as educational resources for K-12 teachers, along with corresponding lesson plans to teach students about how our ancestor’s bodies are different from ours. This research explores how morphological variation throughout the skeleton informs the taxonomic assessment of genus Homo. Several skeletal specimens, including modern humans, Neandertals, the small-bodied species from Indonesia (H. floresiensis), the newly discovered South African fossils (H. naledi), and others will be 3D scanned using state-of-the-art technology for analysis with novel methods such as geometric morphometric statistical analyses. Further, this data will be compared to the Fellow’s previous dataset of macaque monkeys in order to compare how much variation feasibly exists in a geographically widespread primate species. This project tests two hypothesis: (H1) the morphological variation seen in genus Homo mimics what is observed intra-generically in comparable primate species and (H2) postcranial bones, particularly the limb girdles and associated bones, reflect sub-generic taxonomy which can be used for taxonomic assessment. This research advances the career of a woman scientist and undergraduate students from underrepresented areas in STEM will be recruited to help with the project. Results will be disseminated to K-12 students from historically underrepresented groups via lesson plans following NC education standards. Public outreach also will be achieved through blog posts, workshops, and seminar presentations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.