Big Think Interview With Donald Johanson

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Donald Johanson: \r\nSure.  I’m Don Johanson,\r\nfounding director of the Institute of Human Origins.

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Question: How do scientists locate and recover fossils?

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Donald Johanson: \r\nWell I think when someone sees a brand-new discovery, for example in the\r\npages of a National Geographic magazine or whatever, they think you just kind\r\nof travel out there and look around and run into one of these bones and it’s\r\nalmost by luck that one finds these things, but we apply a pretty strategic\r\nplan to surveying and completely scouring an area.  We will map out an area on aerial photographs and\r\nsystematically work through the various grid system that we set up, spend three\r\nor four days in an area the size of a New York City block for example with\r\nmaybe five or six people and the only way to find a fossil is to look and look\r\nand look and look and hope that the light is right, that you’re concentrating\r\non a particular spot and once you find something you then kneel down, have a\r\nclose look at it.  Before you even\r\npick it up make a photograph, map it exactly.  Now of course we can use GPS units and in the case of a\r\nfossil that has been broken, you try to keep people out of the area, so that\r\nthere 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\r\nphotograph it and bag it and bring it back to the research camp where we\r\nidentify it, catalog it and actually photograph it in more detail. 

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Question: In what ways is new technology making the search\r\nfor fossils easier?

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Donald Johanson: \r\nWell there is nothing really that helps us search for fossils.  We can use satellite imagery to\r\neliminate areas that are where there are volcanic rocks for example.  Fossils are best preserved in\r\nsedimentary rocks like sands and silts and things like that and they leave a\r\nparticular signature in these aerial photographs, so we know where not to go\r\nand we know where we might have a possibility.  So that finding fossils themselves still involves all of the\r\nground survey, going out, making preliminary surveys in a vehicle, finding a\r\nplace that has fossils then concentrating on that area and searching day in and\r\nday out and then ultimately determining whether or not we should any\r\nexcavations.  Sometimes we actually\r\ndo excavation.  In the case of the\r\nLucy skeleton that I found in ’74, most of her was exposed on the surface.  She had been eroded out by the\r\nrainstorms in the area, but other places we’ve had to do significant\r\nexcavation.

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Question: What was the scientific significance of the “Lucy”\r\nfind?

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Donald Johanson: \r\nWell I think Lucy’s position on the human family tree is what is most\r\nimportant.  We proposed way back in\r\n1981 in an article in Science that Lucy was the last common ancestor, her\r\nspecies, the tongue twister, Australopithecus afarensis, named after the Afar\r\nregion where she was discovered. \r\nThat she was the last common ancestor to branches that led to us as well\r\nas branches that went extinct and today that position has been solidified by\r\nthe fact that we found nearly 400 specimens of her species, that she is that\r\nimportant bridge between much more ancient and more ape like looking ancestors\r\nand more specialized or derived species like other species of Australopithecus\r\nand also our own genus homo.  So\r\nher position on the family tree has been solidified and that is probably the\r\nsingle most important thing about her, that she gives us a real glimpse as\r\nthese 400 specimens do of what that species looked like at about between three\r\nand four million years ago.

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Question: What would “Lucy,” and others of her species, have\r\nbeen like in person? 

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Donald Johanson: \r\nWell Lucy herself, if we were… I stopped to pick up a cup of coffee out\r\nfront, you know, I was looking down the street.  Now if we saw her walking down the street, as opposed to the\r\naverage New Yorker she would have been very short, about three and a half feet\r\ntall.  She, I would suspect,\r\nalthough we have no definitive proof of this, but because of her antiquity and\r\nbecause of the fact that she probably lived a lifestyle much more like present\r\nday chimpanzees, was probably fairly hairy.  She had a very projecting face, a very ape like face, rather\r\nsloping forehead and a very small skull. \r\nHer brain would have been about the size of an average grapefruit for\r\nexample.  A modern human’s skull is\r\nabout 1,400 cubic centimeters.  Her\r\nbrain was less than 400 cubic centimeters.  She would have been walking upright.  One thing we would have noticed right\r\naway is that she had relatively long arms.  Her arms would have come down almost to her knees, so that’s\r\nkind of evolutionary baggage which is leftover from the time that her ancestors\r\nwere living in the trees.  Probably\r\nlived in a group, I don’t think she was living as a solitary individual, living\r\nmost of the daylight hours I imagine on the ground, although it’s not\r\nimpossible that she and other members of her species would make nests in the\r\ntrees at night.  At three and a\r\nhalf feet in stature it’s much safer to be sleeping up in the trees than on the\r\nground.  If she had a male member\r\nof her species with her the male would have been more like five feet tall.  Lucy would have weighed maybe 60\r\npounds.  A male would have weighed\r\nup to 100 pounds.  Maybe their\r\nlarge size had something to do with their protection of the troop that Lucy and\r\nher other members of her species were living in.  They lived in more forest environments and that is\r\ninteresting because our traditional view when we look at television\r\ndocumentaries on human evolution we see the earliest human ancestors walking\r\nout on the grasslands and we get the idea that that’s where they first became\r\nupright.  That’s where they first\r\nevolved, but now since 1974, ’75 collecting the fossil animals that are found\r\nwith Lucy, the kinds of antelopes for example, the kinds of pigs, looking at\r\nfossil pollen we know that it was much more forested and that these early\r\nupright walking ancestors lived in a more forested environment, much like the\r\nancestors who are living in a forest. \r\nThey were undoubtedly essentially vegetarians, relying to a large degree\r\non probably fruit, but I would also suspect that from time to time they used\r\ntwigs and blades of grass like chimpanzees do to extract termites.  They would have eaten small\r\nvertebrates.  They would have eaten\r\nbird’s eggs and in the case of Lucy in the same layer, the same strata where we\r\nfound her we found fossilized crocodile and turtle eggs.  Maybe she had been watching a crocodile\r\nlay eggs or a turtle and gone down to the edge of the lake where she died and\r\nwas digging those up and was perhaps taken, you know unawares by a crocodiles.  But basically they were vegetarians\r\nliving in groups in much more forested areas.

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Question: Is it true that “Lucy” was named after “Lucy in\r\nthe Sky With Diamonds”?

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Donald Johanson: \r\nThe origins of Lucy’s name. \r\nI had a girlfriend on the expedition whose name was Pamela, and we were\r\ncelebrating the discovery.  Of\r\ncourse this was a major discovery. \r\nHere is 40% of a skeleton, 3.2 million years old.  It was pretty mind-blowing, and I had\r\nbeen, always had been a great Beatles fan, so we had Beatles tapes playing on a\r\nlittle Sony tape recorder, and the “Sergeant Pepper’s Lonely Hearts Club Band” album\r\nwas playing and “Lucy in the Sky with Diamonds” was playing and Pamela said,\r\n“Well if you think that this specimen is a female why don’t you name her\r\nLucy?”  And I thought wow, well you\r\nknow, I’m a scientist.  It should\r\nhave a scientific name.  I just got\r\nmy PhD at the University of Chicago. \r\nWe shouldn’t give cute little names to these fossils.  Yet, it was too late.  Once that word was uttered the next\r\nmorning at breakfast students said, “Are we going back to the Lucy site?”  “Do you think we’ll find more of Lucy’s\r\nskull?”  “How old do you think Lucy\r\nwas when she died?”  And all of a\r\nsudden she started to become a personality.  She was identifiable as an individual.  She was not just Afar Locality 288,\r\nwhich is the entry in our log book. \r\nThat’s her catalog number. \r\nShe became a person and a personality, and what is interesting about that\r\nis I think if we sat around the table and said, “Well what should we name this\r\nspecimen?”  “Should we give it a\r\nname?” it never would have worked,\r\nso it was just pure serendipity, the name stuck.

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Question: What is the scientific legacy of the “First\r\nFamily” discovery? 

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Donald Johanson: \r\nIt’s interesting that you bring up the question of the First Family\r\nbecause First Family was found in 1975 and it’s my belief that if we had found\r\nthose fossils first they might have become even more famous than the Lucy\r\nskeleton.  Lucy is sort of the\r\nbenchmark by which people judge the field of paleoanthropology and the study of\r\nhuman origins.  It’s like when you\r\npick up the “New York Times” and on the front John Noble Wilford has got an\r\narticle about a new fossil and you’re at dinner and someone says, “Well I don’t\r\nknow very much about that.”  “And\r\nyou say well you know it’s older than Lucy.”  And they go, “Oh, older than Lucy.”  You know it’s a reference point, but\r\nthe First Family site, which was found the following year by a medical doctor\r\nwho was on the expedition.  He was\r\nout surveying, walking, spotted a block of rock with a couple of teeth in it\r\nand here we have the remains of somewhere between 13 and 17 individuals from\r\none geological horizon.  A little\r\nbit older than Lucy, maybe you know tens of thousands of years older, but they\r\nweren’t complete fossils.  They\r\nweren’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\r\nof Lucy’s species that had been living together.  There were two infants that looked like they could almost be\r\ntwins 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\r\nFamily is it gave us an idea of biological variation.  If we look at people today for example, just walk a city\r\nblock in New York, you see there is a variation in stature.  There is a variation in\r\nphysiognomy.  There is a variation\r\nin if you could look into their mouths and into the shape of teeth and so\r\non.  Well here was a population and\r\nnothing like that has ever been found before or ever found since.  This is a unique snapshot.  This is a moment when a group of\r\ncreatures at about 3.2 million years ago, a little bit older than Lucy suffered\r\nsome extraordinary catastrophic event. \r\nWe don’t know what that was. \r\nWe thought it was a flash flood, but the geology isn’t right for\r\nthat.  We don’t know why they all\r\ndied, but it’s a mass death and it allows us to solidify the hypothesis that\r\nLucy’s species was typified by having large males and small females.  They’re not two different species.  They’re just variations on a species,\r\nlarge one males, small ones females. \r\nThis is a discovery that I think today in 2010 really deserves\r\nrevisiting 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\r\nbiologically more important than the discovery of a single skeleton for\r\nexample.

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Question: If the discovery were to be revisited, what\r\nquestions could it answer?

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Donald Johanson: \r\nWell I think there are a number of questions.  One of them would be to see if there is any detailed work\r\nthat can be done on surface damage that might tell us something about how long\r\nthey were out on the surface after they died, perhaps how they died.  So far we have not seen carnivore damage\r\non it, so we don’t see the typical hyena chewing that you see on some of these,\r\nbut is there anything on the surfaces of the bone that might help us understand\r\nhow those bones came to be where we found them?  The other thing I think that would be interesting is to use\r\nnew technology that is available in the scanning area where you can use micro\r\nscans and scan these bones almost micron by micron that would give us some\r\nideas about growth rate and this would be particularly true of the teeth.  There is a three-quarters of a baby\r\nskull that is distorted and broken. \r\nThat really needs to be reconstructed to give us an idea of what we\r\nthink a three year-old really looked like.  There has been a discovery at another site very close to\r\nwhere Lucy was found of a nearly complete baby skull by my colleague at the\r\nCalifornia Academy of Sciences, an extraordinary Ethiopian skull, a wonderful\r\nman by the name of Zeresenay Alemseged, who has found a 3.3 million year-old\r\nbaby, so I think there are going to be a lot of things that would come out of\r\nthis, and it’s almost a project in itself.

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Question: When and where did the first recognizably modern\r\nhumans appear?

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Donald Johanson: \r\nYeah, that’s a…  The\r\nappearance of modern, or of homo sapiens, of someone you wouldn’t feel too\r\nuncomfortable sitting next to at, say, Lincoln Center, surprising answer\r\nprobably.  Going back to probably\r\nabout 200,000 years now there were fossils found in the late 1960s in Southern\r\nEthiopia in a place called the Kibish or in the Omo region, and those fossils\r\nhave been preserved in the Ethiopian National Museum ever since their discovery\r\nand we thought they were maybe at the most 90,000 years old.  A research team has gone back and dated\r\na geological horizon at the site and they are close to 200,000 years old and\r\nthey have skulls like yours and mine, so they would have appeared with muscles\r\nand flesh and so on very much like we do, so these would justifiably be put\r\ninto our own species, homo sapiens, supposedly wise man and…  I know I question that too every time I\r\nwatch the evening news, but it means that the earliest members of our species\r\nappeared in Africa.  There are also\r\nfossils from Southern Africa that suggest 100 to 150,000 years and we’re beginning\r\nto find evidence in South Africa of things like the use of ochre, the\r\nmanufacture of bone and bone tools, the manufacture of blade tools and various\r\ntechnologies that don’t show up in Europe until 40,000 years old.  Yet, in South Africa there as much as\r\n160,000 years, so homo sapiens can certainly be traced back to at least 160,000\r\nand I would say to somewhere around 200,000 years ago.

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Question: What happened to the Neanderthals, and was it our\r\nfault?

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Donald Johanson: \r\nWell I don’t think we interbred with the Neanderthals at all.  There are some people who think that\r\nthere was some level of interbreeding. \r\nI think that we look so biologically different that we looked and we\r\nacted so different and we culturally were so different that we would not have had\r\ninterbreeding between two species. \r\nI call them Neanderthal homos and Neanderthalensis and modern humans,\r\nhomo sapiens.  Neanderthals evolved\r\nin Europe as an isolated group. \r\nThat is one of the conditions for the development of a new species, that\r\nthey’re isolated genetically by a geographical barrier or whatever from other\r\npopulations, and they evolved and adapted to glacial Europe.  They lived there for a few hundred\r\nthousand years.  We left Africa 40\r\nto 50,000 years ago with a very sophisticated technology, with an incredibly\r\ncreative mind, with division of labor, with a whole series of things that were\r\nvery different from Neanderthals, and when we began to compete with\r\nNeanderthals for game and for territory Neanderthals fled and the latest\r\nsurviving Neanderthals we have are found in Gibraltar at about 28,000 years\r\nago.  So I think that as we moved\r\ninto Europe from the Middle East Neanderthals moved westward, ultimately down\r\ninto the Iberian Peninsula where they hung on until about 28,000 years ago and\r\nultimately went extinct.

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Question: At what point in the evolutionary timeline did\r\nhumans develop creativity?

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Donald Johanson: \r\nYeah, well, everyone when asked that question or ponders that question\r\nimmediately thinks of the beautiful caves in southwest France, the most famous\r\nof course being Lascaux, where you have beautiful polychrome paintings of\r\nanimals on the walls and so on. \r\nThose are only 20,000 years old. \r\nThe work that my colleague at the Institute of Human Origins is doing,\r\nCurtis Marean, in sites on the very southern tip of Africa, he is finding\r\npieces of ochre that are engraved. \r\nThere are no animal pictures them. \r\nThey’re simple geometric designs, small pieces maybe four or five inches\r\nlong.  Ochre could certainly have\r\nbeen used, those little ochre pieces dipped in water and used as a stamp for\r\nexample and maybe that identified those individuals as belonging to the same\r\nclan or the same group.  There is\r\nextensive discovery of ochre pencils and as we know one of the frequent\r\nminerals that is used to decorate… \r\nI was recently with the some Masai people in Southern Tanzania, and it\r\nwas so interesting because I went to a wedding and they used this red earth to\r\npaint their faces, and here I appear, you know, looking very different and really\r\nfeeling like the other, like the outsider, and one of the elderly women came up\r\nto me and started painting my face, and a number of things happened.  The first thing that happened was I\r\nfelt I was included, that I was part of them, that they had accepted me and I\r\nfelt an intimacy with that person. \r\nYou know how it is.  We keep\r\na distance from one another.  We\r\nhave this personal space around us. \r\nDecorating each other has a very interesting byproduct, which is\r\ndeveloping social bonds, and the other thing was that I felt like I could\r\nparticipate and not just simply be an outside observer.  I was there to do photography, but I\r\nfelt like I was involved in that cultural ceremony of Masai marriage, and we\r\nfind these 160,000-year-old, four times as old as Europe, implements of ochre\r\nthat are clearly pencils, so people were decorating one another and themselves\r\nand probably mostly each other, because they didn’t have mirrors, so they were\r\nprobably decorating one another and this was like in a broad sense like when\r\nyou look at nonhuman primates that groom one another.  It’s a way of developing and establishing social contact and\r\nsocial connectiveness and cohesiveness, so the earliest art really goes back to\r\nSouthern Africa.  We find…  A little bit later we find pierced\r\nshells in the Serengeti.  We find\r\nthem in North Africa.  We find them\r\nin the Middle East, so Europe wasn’t really the place where the creative\r\nexplosion happened.  It came along\r\nwith us into Europe and developed over time to the point where you have the\r\nfirst impressionists 25,000 years ago. \r\nI think that is the first sense I had when I walked into Lascaux in the\r\nearly 1980s was, wow, here was a whole age of Impressionism that preceded our\r\nage of Impressionism by 20,000 years.

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Question: How do you assess the impact of human culture on\r\nour species’ evolution?

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Donald Johanson: \r\nBiological evolution as articulated of course by Darwin and Wallace in\r\nthe 1800s explains and now with of course the great subject of genetics, which\r\nreally helps us understand how features are inherited and altered and so\r\non.  Evolution explains **** our\r\nbiological evolution, but human beings are very unique creatures.  As the Dobzhansky said all animals are\r\nunique; humans are the uniquest. And that uniqueness of being human, language,\r\nart, culture, our dependency on culture for survival, comes from the\r\ncombination of traditional biological evolution.  We look biologically very different from say from Lucy, from\r\nAustralopithecus, from homo erectus, from all these different species, so\r\nbiologically we’ve evolved, but we are culturally just light years away from\r\nNeanderthals, light years away from say early homo sapiens, so that biological\r\nevolution is culture is genetically buried very slow.  We still think I think in many ways with a hunter, gatherer\r\nmentality, but cultural evolution as we know, I mean Paul Lazer, the man who is\r\nmy mentor, he was born in the late 1800s. \r\nImagine what he saw in terms of cultural evolution from the time he was\r\na young teenager to the time when he died in his late ‘80s, so the cultural\r\nevolution has this sort of ratchet aspect to it that once you make a\r\nsignificant leap to say putting information on a little chip that causes a\r\ngiant leap in the way we process information, store information, manipulate\r\ninformation, so that we are a product of both biological and cultural\r\nevolution, which is an extraordinarily powerful combination.  The synergy of those two together is\r\nlike no other creature we have ever seen.

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Question: What modern cultural or environmental changes\r\ncould affect the future of human evolution?

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Donald Johanson: \r\nWell, trying to predict the future biologically and evolutionary as to\r\nwhere we’re going is a very difficult thing, but one thing that we are seeing\r\nis that the species, homo sapiens, which is a global species and that there are\r\ndistinctive differences between different populations.  Some populations have a lighter\r\nskin.  Some populations have darker\r\nskin and some people the epicanthic eye fold and others don’t, but there is more of\r\na homogenization of people today. \r\nThose distinctive features that we see in different populations have\r\narisen because those populations had been isolated.  Well, today the species is interbreeding globally, so there\r\nprobably is going to be more of a homogenization of some of the biological\r\nfeatures as well as some of the features that you mentioned, such as lactose\r\ndeficiency and so on that may ultimately disappear, but I think there will be\r\nmore of a homogenization of the species over time with increased spread of\r\ngenes between disparate populations. 

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Question: What excites you the most about your current\r\nresearch?

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Donald Johanson:  \r\nWell I think the…  I’ve\r\nworked in the earlier periods, three to four million years ago.  What excites me probably more than\r\nanything these days is the emergence of ourselves, the emergence of\r\nanatomically and behaviorally modern humans.  For many years we thought that this was an explosive\r\nmoment.  It was called the cultural\r\nexplosion or whatever, the cognitive explosion and what we’re beginning to find\r\nis that it is a sort of step by step development and most of those important\r\nsteps were seminal in Africa, and I think that we’re going to be able to flesh\r\nout in much more detail the archeology, the paleoclimate, the biology and the\r\nbehavior of the emergence of that creature, those creatures, early homo\r\nsapiens, that gave rise to all humans today, and it is my sense that all humans\r\ntoday come out of Africa, so by implication, regardless of what we look like on\r\nthe outside, genetically, on the inside, everyone is an African.

Recorded on March 19, 2010
Interviewed by Austin Allen

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A conversation with the paleoanthropologist and founding director of the Institute of Human Origins.

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