On May 5 leading paleoanthropologists Donald Johanson and Richard Leakey came together to discuss human origins and why it matters at the American Museum of Natural History (AMNH) in New York City. CNN's Sanjay Gupta moderated. It is the first time Leakey and Johanson--longtime rivals--have shared a public appearance since 1981. Here's the backstory (from yours truly):
The AMNH auditorium was packed and the museum live-streamed the event. Live-tweeting ensued, using the hashtag #humanorigins. After brief introductions by AMNH president Ellen Futter and Gupta, Leakey and Johanson each gave brief talks before sitting down with Gupta for a discussion. Here's the full 1.5-hour video of the event; Storify highlights follow below.*
Leakey spoke first, focusing on work his family (including parents Louisand Mary, wife Meave and daughter Louise) and collaborators have conducted in East Africa for more than 50 years. He observed that the public often doesn't believe paleoanthropologists' claims about human evolution, in part because a lot of older fossils don't look humanlike, and proposed that scientists take a different tack when talking about our origins.
Leading by example, Leakey proceeded to work his way back from Homo sapiens to "pre-sapiens" species such as Homo erectus (of which the Turkana Boy his team found is a spectacular example) and the even older australopithecines, some of whom left behind the remarkable Laetoli footprints that Mary found. Check out the archival photos and the bios of Richard and other members of the Leakey family on the Leakey Foundation web site for more on the many amazing discoveries they have made over the decades.
Johanson spoke next, emphasizing that all people alive today have ancestries that trace back to Africa.
He then described some of the challenges scientists face in piecing together our origins, noting the questions surrounding creatures that predate the australopithecines and that are said to be the earliest human ancestors--namely, Ardipithecus ("Ardi") from Ethiopia, Orrorin from Kenya, and Sahelanthropus from Chad. He paid special attention to Ardi, asserting that the debate has begun over whether it really belongs in the human family tree.
Johanson then gave an obligatory shout-out to his girl Lucy, the 3.2-million-year-old partial skeleton of Australopithecus afarensis he found in Ethiopia, and also mused about the broader significance of ancient human remains.