Emeritus Curator in the Division of Anthropology at the American Museum of Natural History in New York (USA). He is a systematist who has worked extensively on the very diverse lemurs of Madagascar, as well as on the hominid fossil record, in which he also sees diversity. He is the author of many books on paleoanthropology, most recently Masters of the planet (2012) and The strange case of the rickety cossack and other cautionary tales from human evolution (2015).