Doctoral Dissertation Research: Exploration of Positively Selected Regions of the Human Genome Shaping Pelvis and Scapula Evolution

Harvard University, Cambridge MA

Investigators

Abstract

Bones differ in shape and size throughout an animal's body and between animal species, but the underlying genetic mechanisms that result in different looking bones are not well understood. This doctoral dissertation project will investigate DNA "instruction manuals," particularly the "switches" that turn gene expression on or off during development, that result in shape differences in hip and shoulder bones of humans and chimpanzees. The project will advance knowledge about hip and shoulder developmental genetics in the context of modern human skeletal evolution. The project will support graduate research and training; 1-2 undergraduates also will have the opportunity to gain lab experience. The co-PI will use her work in a Life Science Outreach program at Harvard University as an opportunity to discuss this research and other facets of human evolution and genetics with New England high school biology teachers and students, ideally recruiting interested students to visit the lab and serve as summer researchers. The PI and co-PI's close ties with the Harvard Museum of Natural History will allow for the development of public exhibits and events that showcase bone biology, genetics, and human evolution. Researchers have discussed a number of evolutionary pressures, primarily related to the adoption of bipedalism, that are likely to have acted on pelvis and scapula morphology during hominin evolution. However, little is known about underlying genomic mechanisms that resulted in the observed changes in the shape and structure of these bones. This project will investigate portions of the genome that were previously identified as having potential activity and regulatory functions during embryonic pelvis and scapula development. The genomic sequences being specifically investigated overlap with regions of DNA that show signs of having been under positive selection in the human lineage. For each of these regulatory sequences, the researchers will test whether the human and chimpanzee versions of the sequence control gene activity, and whether there are differences in gene activity between the two species. This work will help to identify sequences likely to have been under selection during human evolution to produce the modern human pelvis and scapula. 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.