Animals started evolving long before showing up as fossils
A new effort to date the early history of modern animals finds a lot of evolutionary dawdling.
The last common ancestor of all living animals probably arose nearly 800 million years ago, a multidisciplinary research team reports in the Nov. 25 Science. From that common ancestry, various animal lineages diverged and evolved on their own paths. Yet the major animal groups living today didn’t arise until roughly 200 million years later, in an exuberant burst of forms prese