Postdoc, Katrina Jones and Prof. Stephanie Pierce teamed with the Field Museum of Natural History to find how and when changes happened in the spine of mammals during evolution. Jones says the study, published in Nature Ecology & Evolution, tries to answer a fundamental evolutionary question, "How does a relatively simple structure evolve into a complex one that can do lots of different things?"
A combination of developmental changes and adaptive pressures led to the diversity of backbones in mammals today. In a previous study from 2018, Pierce and Jones showed that though vertebrae looks very similar in early mammal ancestors, there are subtle differences that create distinct developmental regions. With the 2019 study, they reveal that those distinct regions provided the raw material that facilitated functional differentiation. According to Pierce, "If you don't have these distinct development regions in place and you have a selective pressure, all the vertebrae are going to adapt in the same way." Phys.org