There are these jaw-dropping moments in the life of a scientist. . . You can feel in your brain how all these preconceived ideas you had start falling to pieces.
So said neurobiologist Christoph Zollikofer in response to the discovery of a 1.8 million year old hominid skull at Dmanisi in Georgia. As reported recently in the Wall Street Journal, this perfectly preserved “early human” skull provides evidence that a single hominid species, Homo erectus, emerged out of Africa about 2 million years ago. Dr. Zollikofer is excited because the discovery simplifies the paleontologist’s tree of hominid species dramatically.