Donald Johanson: Sure. I’m Don Johanson, founding director of the Institute of Human Origins.
Question: How do scientists locate and recover fossils?
Donald Johanson: Well I think when someone sees a brand-new discovery, for example in the pages of a National Geographic magazine or whatever, they think you just kind of travel out there and look around and run into one of these bones and it’s almost by luck that one finds these things, but we apply a pretty strategic plan to surveying and completely scouring an area. We will map out an area on aerial photographs and systematically work through the various grid system that we set up, spend three or four days in an area the size of a New York City block for example with maybe five or six people and the only way to find a fossil is to look and look and look and look and hope that the light is right, that you’re concentrating on a particular spot and once you find something you then kneel down, have a close look at it. Before you even pick it up make a photograph, map it exactly. Now of course we can use GPS units and in the case of a fossil that has been broken, you try to keep people out of the area, so that there is no damage done to any of the bone fragments and you set up a micro-grid system, so that you map every piece and number it as you pick it up and photograph it and bag it and bring it back to the research camp where we identify it, catalog it and actually photograph it in more detail.
Question: In what ways is new technology making the search for fossils easier?
Donald Johanson: Well there is nothing really that helps us search for fossils. We can use satellite imagery to eliminate areas that are where there are volcanic rocks for example. Fossils are best preserved in sedimentary rocks like sands and silts and things like that and they leave a particular signature in these aerial photographs, so we know where not to go and we know where we might have a possibility. So that finding fossils themselves still involves all of the ground survey, going out, making preliminary surveys in a vehicle, finding a place that has fossils then concentrating on that area and searching day in and day out and then ultimately determining whether or not we should any excavations. Sometimes we actually do excavation. In the case of the Lucy skeleton that I found in ’74, most of her was exposed on the surface. She had been eroded out by the rainstorms in the area, but other places we’ve had to do significant excavation.
Question: What was the scientific significance of the “Lucy” find?
Donald Johanson: Well I think Lucy’s position on the human family tree is what is most important. We proposed way back in 1981 in an article in Science that Lucy was the last common ancestor, her species, the tongue twister, Australopithecus afarensis, named after the Afar region where she was discovered. That she was the last common ancestor to branches that led to us as well as branches that went extinct and today that position has been solidified by the fact that we found nearly 400 specimens of her species, that she is that important bridge between much more ancient and more ape like looking ancestors and more specialized or derived species like other species of Australopithecus and also our own genus homo. So her position on the family tree has been solidified and that is probably the single most important thing about her, that she gives us a real glimpse as these 400 specimens do of what that species looked like at about between three and four million years ago.
Question: What would “Lucy,” and others of her species, have been like in person?
Donald Johanson: Well Lucy herself, if we were… I stopped to pick up a cup of coffee out front, you know, I was looking down the street. Now if we saw her walking down the street, as opposed to the average New Yorker she would have been very short, about three and a half feet tall. She, I would suspect, although we have no definitive proof of this, but because of her antiquity and because of the fact that she probably lived a lifestyle much more like present day chimpanzees, was probably fairly hairy. She had a very projecting face, a very ape like face, rather sloping forehead and a very small skull. Her brain would have been about the size of an average grapefruit for example. A modern human’s skull is about 1,400 cubic centimeters. Her brain was less than 400 cubic centimeters. She would have been walking upright. One thing we would have noticed right away is that she had relatively long arms. Her arms would have come down almost to her knees, so that’s kind of evolutionary baggage which is leftover from the time that her ancestors were living in the trees. Probably lived in a group, I don’t think she was living as a solitary individual, living most of the daylight hours I imagine on the ground, although it’s not impossible that she and other members of her species would make nests in the trees at night. At three and a half feet in stature it’s much safer to be sleeping up in the trees than on the ground. If she had a male member of her species with her the male would have been more like five feet tall. Lucy would have weighed maybe 60 pounds. A male would have weighed up to 100 pounds. Maybe their large size had something to do with their protection of the troop that Lucy and her other members of her species were living in. They lived in more forest environments and that is interesting because our traditional view when we look at television documentaries on human evolution we see the earliest human ancestors walking out on the grasslands and we get the idea that that’s where they first became upright. That’s where they first evolved, but now since 1974, ’75 collecting the fossil animals that are found with Lucy, the kinds of antelopes for example, the kinds of pigs, looking at fossil pollen we know that it was much more forested and that these early upright walking ancestors lived in a more forested environment, much like the ancestors who are living in a forest. They were undoubtedly essentially vegetarians, relying to a large degree on probably fruit, but I would also suspect that from time to time they used twigs and blades of grass like chimpanzees do to extract termites. They would have eaten small vertebrates. They would have eaten bird’s eggs and in the case of Lucy in the same layer, the same strata where we found her we found fossilized crocodile and turtle eggs. Maybe she had been watching a crocodile lay eggs or a turtle and gone down to the edge of the lake where she died and was digging those up and was perhaps taken, you know unawares by a crocodiles. But basically they were vegetarians living in groups in much more forested areas.
Question: Is it true that “Lucy” was named after “Lucy in the Sky With Diamonds”?
Donald Johanson: The origins of Lucy’s name. I had a girlfriend on the expedition whose name was Pamela, and we were celebrating the discovery. Of course this was a major discovery. Here is 40% of a skeleton, 3.2 million years old. It was pretty mind-blowing, and I had been, always had been a great Beatles fan, so we had Beatles tapes playing on a little Sony tape recorder, and the “Sergeant Pepper’s Lonely Hearts Club Band” album was playing and “Lucy in the Sky with Diamonds” was playing and Pamela said, “Well if you think that this specimen is a female why don’t you name her Lucy?” And I thought wow, well you know, I’m a scientist. It should have a scientific name. I just got my PhD at the University of Chicago. We shouldn’t give cute little names to these fossils. Yet, it was too late. Once that word was uttered the next morning at breakfast students said, “Are we going back to the Lucy site?” “Do you think we’ll find more of Lucy’s skull?” “How old do you think Lucy was when she died?” And all of a sudden she started to become a personality. She was identifiable as an individual. She was not just Afar Locality 288, which is the entry in our log book. That’s her catalog number. She became a person and a personality, and what is interesting about that is I think if we sat around the table and said, “Well what should we name this specimen?” “Should we give it a name?” it never would have worked, so it was just pure serendipity, the name stuck.
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.
Question: When and where did the first recognizably modern humans appear?
Donald Johanson: Yeah, that’s a… The appearance of modern, or of homo sapiens, of someone you wouldn’t feel too uncomfortable sitting next to at, say, Lincoln Center, surprising answer probably. Going back to probably about 200,000 years now there were fossils found in the late 1960s in Southern Ethiopia in a place called the Kibish or in the Omo region, and those fossils have been preserved in the Ethiopian National Museum ever since their discovery and we thought they were maybe at the most 90,000 years old. A research team has gone back and dated a geological horizon at the site and they are close to 200,000 years old and they have skulls like yours and mine, so they would have appeared with muscles and flesh and so on very much like we do, so these would justifiably be put into our own species, homo sapiens, supposedly wise man and… I know I question that too every time I watch the evening news, but it means that the earliest members of our species appeared in Africa. There are also fossils from Southern Africa that suggest 100 to 150,000 years and we’re beginning to find evidence in South Africa of things like the use of ochre, the manufacture of bone and bone tools, the manufacture of blade tools and various technologies that don’t show up in Europe until 40,000 years old. Yet, in South Africa there as much as 160,000 years, so homo sapiens can certainly be traced back to at least 160,000 and I would say to somewhere around 200,000 years ago.
Question: What happened to the Neanderthals, and was it our fault?
Donald Johanson: Well I don’t think we interbred with the Neanderthals at all. There are some people who think that there was some level of interbreeding. I think that we look so biologically different that we looked and we acted so different and we culturally were so different that we would not have had interbreeding between two species. I call them Neanderthal homos and Neanderthalensis and modern humans, homo sapiens. Neanderthals evolved in Europe as an isolated group. That is one of the conditions for the development of a new species, that they’re isolated genetically by a geographical barrier or whatever from other populations, and they evolved and adapted to glacial Europe. They lived there for a few hundred thousand years. We left Africa 40 to 50,000 years ago with a very sophisticated technology, with an incredibly creative mind, with division of labor, with a whole series of things that were very different from Neanderthals, and when we began to compete with Neanderthals for game and for territory Neanderthals fled and the latest surviving Neanderthals we have are found in Gibraltar at about 28,000 years ago. So I think that as we moved into Europe from the Middle East Neanderthals moved westward, ultimately down into the Iberian Peninsula where they hung on until about 28,000 years ago and ultimately went extinct.
Question: At what point in the evolutionary timeline did humans develop creativity?
Donald Johanson: Yeah, well, everyone when asked that question or ponders that question immediately thinks of the beautiful caves in southwest France, the most famous of course being Lascaux, where you have beautiful polychrome paintings of animals on the walls and so on. Those are only 20,000 years old. The work that my colleague at the Institute of Human Origins is doing, Curtis Marean, in sites on the very southern tip of Africa, he is finding pieces of ochre that are engraved. There are no animal pictures them. They’re simple geometric designs, small pieces maybe four or five inches long. Ochre could certainly have been used, those little ochre pieces dipped in water and used as a stamp for example and maybe that identified those individuals as belonging to the same clan or the same group. There is extensive discovery of ochre pencils and as we know one of the frequent minerals that is used to decorate… I was recently with the some Masai people in Southern Tanzania, and it was so interesting because I went to a wedding and they used this red earth to paint their faces, and here I appear, you know, looking very different and really feeling like the other, like the outsider, and one of the elderly women came up to me and started painting my face, and a number of things happened. The first thing that happened was I felt I was included, that I was part of them, that they had accepted me and I felt an intimacy with that person. You know how it is. We keep a distance from one another. We have this personal space around us. Decorating each other has a very interesting byproduct, which is developing social bonds, and the other thing was that I felt like I could participate and not just simply be an outside observer. I was there to do photography, but I felt like I was involved in that cultural ceremony of Masai marriage, and we find these 160,000-year-old, four times as old as Europe, implements of ochre that are clearly pencils, so people were decorating one another and themselves and probably mostly each other, because they didn’t have mirrors, so they were probably decorating one another and this was like in a broad sense like when you look at nonhuman primates that groom one another. It’s a way of developing and establishing social contact and social connectiveness and cohesiveness, so the earliest art really goes back to Southern Africa. We find… A little bit later we find pierced shells in the Serengeti. We find them in North Africa. We find them in the Middle East, so Europe wasn’t really the place where the creative explosion happened. It came along with us into Europe and developed over time to the point where you have the first impressionists 25,000 years ago. I think that is the first sense I had when I walked into Lascaux in the early 1980s was, wow, here was a whole age of Impressionism that preceded our age of Impressionism by 20,000 years.
Question: How do you assess the impact of human culture on our species’ evolution?
Donald Johanson: Biological evolution as articulated of course by Darwin and Wallace in the 1800s explains and now with of course the great subject of genetics, which really helps us understand how features are inherited and altered and so on. Evolution explains **** our biological evolution, but human beings are very unique creatures. As the Dobzhansky said all animals are unique; humans are the uniquest. And that uniqueness of being human, language, art, culture, our dependency on culture for survival, comes from the combination of traditional biological evolution. We look biologically very different from say from Lucy, from Australopithecus, from homo erectus, from all these different species, so biologically we’ve evolved, but we are culturally just light years away from Neanderthals, light years away from say early homo sapiens, so that biological evolution is culture is genetically buried very slow. We still think I think in many ways with a hunter, gatherer mentality, but cultural evolution as we know, I mean Paul Lazer, the man who is my mentor, he was born in the late 1800s. Imagine what he saw in terms of cultural evolution from the time he was a young teenager to the time when he died in his late ‘80s, so the cultural evolution has this sort of ratchet aspect to it that once you make a significant leap to say putting information on a little chip that causes a giant leap in the way we process information, store information, manipulate information, so that we are a product of both biological and cultural evolution, which is an extraordinarily powerful combination. The synergy of those two together is like no other creature we have ever seen.
Question: What modern cultural or environmental changes could affect the future of human evolution?
Donald Johanson: Well, trying to predict the future biologically and evolutionary as to where we’re going is a very difficult thing, but one thing that we are seeing is that the species, homo sapiens, which is a global species and that there are distinctive differences between different populations. Some populations have a lighter skin. Some populations have darker skin and some people the epicanthic eye fold and others don’t, but there is more of a homogenization of people today. Those distinctive features that we see in different populations have arisen because those populations had been isolated. Well, today the species is interbreeding globally, so there probably is going to be more of a homogenization of some of the biological features as well as some of the features that you mentioned, such as lactose deficiency and so on that may ultimately disappear, but I think there will be more of a homogenization of the species over time with increased spread of genes between disparate populations.
Question: What excites you the most about your current research?
Donald Johanson: Well I think the… I’ve worked in the earlier periods, three to four million years ago. What excites me probably more than anything these days is the emergence of ourselves, the emergence of anatomically and behaviorally modern humans. For many years we thought that this was an explosive moment. It was called the cultural explosion or whatever, the cognitive explosion and what we’re beginning to find is that it is a sort of step by step development and most of those important steps were seminal in Africa, and I think that we’re going to be able to flesh out in much more detail the archeology, the paleoclimate, the biology and the behavior of the emergence of that creature, those creatures, early homo sapiens, that gave rise to all humans today, and it is my sense that all humans today come out of Africa, so by implication, regardless of what we look like on the outside, genetically, on the inside, everyone is an African.
Recorded on March 19, 2010
Interviewed by Austin Allen