Modern humans have relatively lightly built gracile skeletons compared to other primates and earlier hominins. The goal of this research is to assess the effects of reduced mobility and physical activity on human skeletal variation and gracility in a large sample of human groups. In this collaborative research, we are characterizing variation in trabecular and cortical bone structure across multiple elements in the human postcranial skeleton in relation to variation in subsistence strategy, mobility, and physical activity. In addition, we are evaluating the effects of specific, intensive habitual physical activities on bone structure in living humans to use as a model for understanding behavioral patterns in the past. Collectively, this work aims to assess changes in bone structure and mass through space and time to disentangle the interactions among subsistence strategy, mobility, habitual activity as well as begin to address questions related to diet and ancestry.
Collaborating Researchers
Kristian Carlson, University of Southern California
Jay Stock, University of Western Ontario
Adam Gordon, University at Albany
Tea Jashashvili, University of Southern California
Jaap Saers, Cambridge University
Mark Dowdeswell, University of Witwatersrand
Publications
2020
Saers JP, DeMars LJ, Stephens NB, Jashashvili T, Carlson KJ, Gordon AD, Ryan TM, Stock JT. Automated resolution independent method for comparing in vivo and dry trabecular bone. American Journal of Physical Anthropology. https://doi.org/10.1002/ajpa.24181
Saers JP, DeMars LJ, Stephens NB, Jashashvili T, Carlson KJ, Gordon AD, Shaw CN*, Ryan TM, Stock JT. Combinations of trabecular and cortical bone properties distinguish various loading modalities between athletes and controls. American Journal of Physical Anthropology. https://doi.org/10.1002/ajpa.24176
DeMars, L. J., Stephens, N. B., Saers, J. P., Gordon, A., Stock, J. T., & Ryan, T. M. Using point clouds to investigate the relationship between trabecular bone phenotype and behavior: An example utilizing the human calcaneus. American Journal of Human Biology, e23468.
2019
Doershuk, L. J., Saers, J. P. P., Shaw, C. N., Jashashvili, T., Carlson, K. J., Stock, J. T., & Ryan, T.M. Complex variation of trabecular bone structure in the proximal humerus and femur of five modern human populations. American Journal of Physical Anthropology 168, 104-118.
2016
Saers, J.P., Cazorla-Bak, Y., Shaw, C.N., Stock, J.T., Ryan, T.M. Trabecular bone structural variation throughout the human lower limb. Journal of Human Evolution 97, 97-108.
2015
Ryan, T. M., & Shaw, C. N. Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading. Proceedings of the National Academy of Sciences of the USA 112, 372-377.