Gabrielle A. Russo

Gabrielle’s dissertation research (funded by a NSF Doctoral Dissertation Improvement Grant, a Leakey Foundation General Research Grant and two College of Liberal Arts Graduate Research Fellowships) examines three novel changes in spinal anatomy that occurred during the course of hominoid (apes and humans) evolution: tail loss, the adoption of upright trunk posture, and adaptations to bipedal locomotion. These events are important to physical anthropology because they mark the evolutionary appearance of the first apes, apes of a modern aspect, and the hominin clade, respectively. However, the anatomical evidence central to identifying their earliest possible occurrences remains controversial. Gabrielle suggests that such difficulties persist in part because we lack appropriate extant primate analogs for comparisons.

Her dissertation research addresses these issues by examining the anatomy associated with tail length, posture and locomotion independent of one another, and in the context of a taxonomically and morphologically diverse sample. Her research approach is innovative for a number of reasons. First, she examines the sacrum--an understudied skeletal element that occupies a functionally important anatomical position as part of both the pelvis and spine, and serves as the tail’s sole bony link to the rest of the body. Second, using high resolution X-ray computed tomography scans in addition to traditional morphometric analyses of external bony features, she quantifies cortical and trabecular bone parameters to evaluate how the sacrum’s epigenetically sensitive internal architecture responds to and reflects dynamic loading induced by spinal column weight transmission and tail movement. Third, she evaluates changes in nonprehensile tail anatomy associated with tail reduction to gain additional insight into the anatomy associated with tail loss. The results of this research will be used to make inferences about the trunk posture, locomotion and tail lengths of a number of fossil primates.

The findings from her studies may have implications for our understanding of ape and hominin origins, evolutionary relationships and behaviors. Results from this project will be disseminated to the scientific community through peer-reviewed journals in physical anthropology and biology. Part of her dissertation research has already been published in the Journal of Human Evolution.

Gabrielle was awarded external research funding from The National Science Foundation and The Leakey Foundation to conduct her dissertation study. With research funding secured and the support of the continuing fellowship, she feels that she is on track to defend her dissertation by Spring 2013.