In our own primate branch of the tree of life we can see the parallel tracks of virus and host evolution. About 40 million years ago, the ancestors of monkeys that live in Central and South America split off from the ancestors of monkeys and apes in Africa, Europe, and Asia. The papillomaviruses that infect living primates show the same split. Our papillomaviruses, for example, are more closely related to those of baboons in Kenya than those of howler monkeys in the Amazon.
