Why do mammals have a stiff lower jaw?

Professor of Integrative Biology, Jack Tseng, and IB graduate student Sergio Garcia Lara, co-authored a paper in the journal Philosophical Transactions of the Royal Society B as part of a series on the evolution of the mammalian skull. The study was based on a database they created of more than 1,000 vertebrate jaws. Read more here...

UC Berkeley doctoral student Sergio Garcia Lara, a co-author of the paper, stands next to a gray whale jawbone while holding a glass vial containing a bat jaw. The comparison highlights the variety of jaw sizes and shapes that have evolved in mammals, despite the fact that they reduced the number of bones in the lower jaw to one per side, unlike most other vertebrates. (Photo credit: Jack Tseng)