The group of fossils Don Johanson found in 1975 marked a watershed in the study of human origins—and deserves to be revisited today.
Question: What is the scientific legacy of the “First Family” discovery?
Donald Johanson: It’s interesting that you bring up the question of the First Family because First Family was found in 1975 and it’s my belief that if we had found those fossils first they might have become even more famous than the Lucy skeleton. Lucy is sort of the benchmark by which people judge the field of paleoanthropology and the study of human origins. It’s like when you pick up the “New York Times” and on the front John Noble Wilford has got an article about a new fossil and you’re at dinner and someone says, “Well I don’t know very much about that.” “And you say well you know it’s older than Lucy.” And they go, “Oh, older than Lucy.” You know it’s a reference point, but the First Family site, which was found the following year by a medical doctor who was on the expedition. He was out surveying, walking, spotted a block of rock with a couple of teeth in it and here we have the remains of somewhere between 13 and 17 individuals from one geological horizon. A little bit older than Lucy, maybe you know tens of thousands of years older, but they weren’t complete fossils. They weren’t complete individuals I should say, but they were adults. They were infants. They were males and females. This was a group of afarensis, a group of Lucy’s species that had been living together. There were two infants that looked like they could almost be twins when you look at the teeth for example. There were large males and there were small adults. The small adults were females. So what was important about the First Family is it gave us an idea of biological variation. If we look at people today for example, just walk a city block in New York, you see there is a variation in stature. There is a variation in physiognomy. There is a variation in if you could look into their mouths and into the shape of teeth and so on. Well here was a population and nothing like that has ever been found before or ever found since. This is a unique snapshot. This is a moment when a group of creatures at about 3.2 million years ago, a little bit older than Lucy suffered some extraordinary catastrophic event. We don’t know what that was. We thought it was a flash flood, but the geology isn’t right for that. We don’t know why they all died, but it’s a mass death and it allows us to solidify the hypothesis that Lucy’s species was typified by having large males and small females. They’re not two different species. They’re just variations on a species, large one males, small ones females. This is a discovery that I think today in 2010 really deserves revisiting and going back and doing a detailed analysis of the specimens. It is a unique snapshot. It is one of the things that is for us biologically more important than the discovery of a single skeleton for example.
Question: If the discovery were to be revisited, what questions could it answer?
Donald Johanson: Well I think there are a number of questions. One of them would be to see if there is any detailed work that can be done on surface damage that might tell us something about how long they were out on the surface after they died, perhaps how they died. So far we have not seen carnivore damage on it, so we don’t see the typical hyena chewing that you see on some of these, but is there anything on the surfaces of the bone that might help us understand how those bones came to be where we found them? The other thing I think that would be interesting is to use new technology that is available in the scanning area where you can use micro scans and scan these bones almost micron by micron that would give us some ideas about growth rate and this would be particularly true of the teeth. There is a three-quarters of a baby skull that is distorted and broken. That really needs to be reconstructed to give us an idea of what we think a three year-old really looked like. There has been a discovery at another site very close to where Lucy was found of a nearly complete baby skull by my colleague at the California Academy of Sciences, an extraordinary Ethiopian skull, a wonderful man by the name of Zeresenay Alemseged, who has found a 3.3 million year-old baby, so I think there are going to be a lot of things that would come out of this, and it’s almost a project in itself.
Recorded on March 19, 2010
Interviewed by Austin Allen