Doctoral Dissertation Research: The Evolutionary Significance of Skeletal Variation in Homo naledi

Duke University, Durham NC

Investigators

Abstract

The recent discovery of the hominin species Homo naledi has introduced new complexity and new questions about human evolution. In this doctoral dissertation project, the investigator will use 3D scanning technology to quantify skeletal variation across a number of H. naledi individuals and situate the results in a broader comparative primate context. Beyond providing an evolutionary context for the variation in H. naledi, this project will highlight the relationship between genetic and skeletal variation at multiple scales, which may be used to identify related individuals within bioarchaeological, forensic, and paleoanthropological assemblages. The research will generate hundreds of 3D models of three primate species, which will be made available to the public, creating new educational materials that can be 3D printed and used for lesson plans and outreach. Additionally, through close collaborations with local and international universities, undergraduates with interests in 3D imaging will continue to engage in independent research projects using these scans. It is not known whether the recently discovered H. naledi individuals represent part of a small, isolated population or a larger, geographically diverse species that may have interacted with modern humans. In this project, the variation between H. naledi individuals will be quantified using 3D geometric morphometric assessment of five postcranial elements. Comparative modern human and chimpanzee samples containing individuals of known and unknown biological relationships will be used as baselines to explore variation at multiple scales. To this end, this project has three objectives: 1) to test the hypothesis that there is a positive relationship between genetic and morphological distance at and below the population level in modern humans and chimpanzees; 2) to quantify the variation within H. naledi and compare it to the variation calculated for modern humans and chimpanzees; and 3) to contextualize this variation by determining the extent to which H. naledi resembles biological relatives. A number of evolutionary scenarios concerning population isolation and relative size will be evaluated to determine which scenario most likely produced the variation seen in H. naledi. In so doing, this project will shed light on H. naledi’s evolutionary history and the possibility of interaction between H. naledi and modern humans. 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.