The Genetics of Jaw Evolution

Article excerpt

A half billion years ago, vertebrates lacked the ability to chew their food. They did not have jaws. Instead, their heads consisted of a flexible, fused basket of cartilage. This week, an international team of researchers led by a faculty member from the University of Colorado at Boulder published evidence that three genes in jawless vertebrates might have been key to the development of jaws in higher vertebrates. The finding is potentially significant in that it might help explain how vertebrates shifted from a life of passive "filter feeding" to one of active predation.

"Essentially, what we found is that the genetic roots of the vertebrate jaw can be found in the embryos of a weird jawless fish called the sea lamprey," said Daniel Meulemans Medeiros, an assistant professor of ecology and evolutionary biology at CU-Boulder and lead author of the study. Lampreys are eel-like fish with no jaws and a "very strange skeleton compared to their cousins" with jaws, Medeiros said. …