The studies have proved that the shape of one's jaw bone is formed over time, not only through genetics, but from repeated use. Therefore, this information can be used to conclude what sort of diet our ancestors had.
"Our research aimed to see how much of the mandible's -- or jaw bone's -- shape is plastic, a response to environmental influences, such as diet, and how much is genetic," informed Megan Holmes, Johns Hopkins Center for Functional Anatomy and Evolution graduate student, and lead author of the published study. "We used archaeological jaw bones from two different regions to answer that question."
"Before we can make inferences about what the shape of a bone tells us," continued Holmes, "like what environment the individual lived in, who it's related to or what it ate, we have to understand what creates that shape. The idea that function influences the shape of jaw bones is great for the archeological record in terms of discovering the diet of a population, and it's also really useful for reconstructing the fossil record -- finding which fossils are related to which, and how."
Chosen groups to study
were the genetically-isolated, American Native tribes, the Arikara and Point Hope. Fossils of these two groups dated all the way back to the 1600's.
The team's results were published online June 23 in the American Journal of Physical Anthropology