Human evolution is a tricky subject, with very little information on who our ancestors were and what they were like. By convention, researchers have defined the evolutionary group Homo (the genus of modern humans) as the first of our ancestors to make and use stone tools; the oldest members of this group, Homo habilis (literally ‘skillful man’) are thought to have existed around 2 million years ago. Just recently, however, researchers at the California Academy of Sciences San Francisco have unearthed what they claim to be stone tools from a much earlier time, around 3.3 million years ago.
What does this mean for Homo? Not much. It’s important to consider a few things before rewriting the textbooks: (1) this discovery was only reported very recently and still needs to be reviewed by other experts in the field, (2) our understanding of human evolutionary history is incomplete, meaning there could very well have been Homo species older than habilis, and (3) the distinction between Homo and earlier human groups is an arbitrary one, and we know that even Chimps use rudimentary stick and stone tools to find and gather food. In summary, this is an exciting discovery if it stands up to scrutiny, but it probably doesn’t require a complete revision of what we know.
Acknowledgments: Special thanks to Bridget Alex from the Department of Anthropology and Human Evolutionary Biology at Harvard University.
Managing Correspondent: Adam Brown, Waves Lead Editor
Original article: Oldest stone tools raise questions about their creators – Nature