## Metadata - Author: [[Ann Gibbons]] - Full Title: The First Human - Category: #books ## Highlights - So when news spread that Brunet had encountered the jawbone of Abel on that January morning in 1995, the discovery reverberated through the paleoanthropological world. It opened a third window into the earliest stages of human evolution, adding central Africa to the view that had encompassed only eastern Africa and South Africa. ([Location 229](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=229)) - White’s silence about the fossils his team has found creates a mystique that spurs more interest in the team’s discoveries; he is an alpha male in a crowd of paleoanthropologists. His rivals keep an eye on him, both intensely curious about what he is doing and wary that they will be stung by his sharp criticism, often thinly veiled as caustic humor. Though most respect his high standard of scholarship and his capacity for hard work, many resent his refusal to offer previews of his fossils or discuss them until he is ready to publish a detailed description—a process that has left the entire field of paleoanthropology in suspense about the identity of the partial skeleton he has been excavating and analyzing in Ethiopia for more than a decade. One colleague calls the Middle Awash research project the “Manhattan Project of Paleoanthropology.” But White will not be pressured or rushed, and he is particularly loath to see researchers speculate about the fossils he has under study until he can publish his analysis and influence the first impressions of the fossils. ([Location 296](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=296)) - In the same way that politicians display photos of themselves posing with prominent colleagues on their walls, White has framed photos of famous fossils he has known that were featured on the covers of Nature, Science, and other leading journals. The most famous of those is the fossil of a small jaw that appeared on the cover of Nature in 1994, showing a milk tooth of what they called an entirely new type of hominid—one that White and his colleagues initially named Australopithecus ramidus, a name that honored the local Afar people, ramidus in their language meaning “root,” suggesting that it was humanity’s root ancestor. At an age of 4.4 million years, this fossil was the first in twenty years to challenge Lucy for her status as the earliest human ancestor. That claim to being the earliest ancestor, however, depended on seventeen fossils, most of which were teeth or jawbone. That meant A. ramidus had earned its place on the human line by the skin of its teeth, as the paleoanthropologist Bernard Wood of George Washington University, a frequent commentator in Nature, wrote in an accompanying article on the new fossils. Although Wood exulted that it looked to him like the long-sought missing link with the ancestor of chimpanzees, others said White had not proved beyond a doubt that A. ramidus was a hominid—he needed bones from the neck down to show how this creature moved through the prehistoric woods where it lived. To pass the traditional litmus test for being a bona fide hominid, it had to walk upright, rather than on its knuckles like a chimpanzee or gorilla. ([Location 327](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=327)) - The vast Afar depression is a magnet for geologists, because it is one of only three places in the world where three giant plates of the earth’s crust intersect, forming a giant Y. The two upper arms of the Y are filled with water—the Red Sea and Gulf of Aden. ([Location 1332](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1332)) - Jon Kalb, an American geologist who would travel with Taieb to Hadar two years later, would describe the scene as “an enormous, flat-lying encyclopedia of natural history with part of one page exposed on this hill, another in that ravine, another on the crest of a ridge. The formidable task ahead of us was to put together the pieces and see how much of any one page we could read.” ([Location 1356](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1356)) - Elephant teeth are particularly useful for getting a quick fix on the age of a site, because they are large and, therefore, plentiful and well preserved. They also have features that change bit by bit over time, so paleontologists can sort them into distinct lineages of extinct elephants whose ages and preferred habitats are well known in Africa for the past 6 million years. This use of index animals such as elephants and pigs to date sites is called faunal dating or biochronology, and it is often used when there are no volcanic minerals to date the sediments where fossils are found—or along with radiometric dating as an independent test of the dates. ([Location 1368](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1368)) - The first real field season at Hadar got off to a slow start. It was the fall of 1973, and half the field season had gone by without the discovery of a hominid. Don Johanson had all but promised the National Science Foundation in his grant application that he would find hominids at Hadar, and now he had spent almost half of his grant money of $43,000 on a Land Rover and supplies for the French-American team. (As a geologist, Taieb got even less funding.) The money was supposed to last for two years. He was young, ambitious, and impatient for a hominid. Even though many paleoanthropologists have had illustrious careers without finding hominids and most teams spend years at a fossil site before seeing evidence of human ancestors, Johanson had yet to prove himself. He doubted that he could renew his grant to work at Hadar if the team found only fossils of pigs and hippos. Johanson was preoccupied with these worries on the afternoon of October 30 as he was surveying an airless little gully with Tom Gray, a graduate student in archaeology at Case Western Reserve University in Cleveland, where Johanson had just been hired as an instructor in anthropology. In a scene that Johanson described vividly in his book Lucy: The Beginnings of Humankind, Johanson idly kicked at what he thought was yet another bit of hippo bone sticking out of the sand. It came loose, and he realized that it was probably the tibia—the shinbone—of a small primate. Johanson picked it up, and as he was recording the spot where he had found it in his field notebook, he noticed another piece of bone a few yards away. This time, it was the lower end of a thighbone. Next to it was a bit of rounded condyle bone from the knee joint. He put the pieces together; they fit perfectly. At first, he thought he had found a monkey’s knee. Then he noticed that the thighbone and shinbone joined most naturally at an angle. He knew that a monkey’s thigh and shinbones fit together one on top of the other, in a straight line. “Almost against my will I began to picture in my mind the skeleton of a human being, and recall the outward slant from knee to thigh that was peculiar to upright walkers,” Johanson wrote. “It dawned on me that this was a hominid fossil.” Other than isolated teeth, the knee bones were Johanson’s first discovery of hominid bones. But the next morning, he began to second-guess his own judgment. He desperately needed a human thighbone for comparison. In a bizarre replay of Harvard paleontologist Bryan Patterson’s raid of a Turkana grave, Johanson would also find a local tribe’s burial mound and take a human thighbone. When he compared the fossil femur and the femur from a dead Afar tribesman, they were virtually identical, except that the fossil thighbone was smaller. He announced his discovery of the fossil at a press conference in Addis Ababa. As soon as Johanson returned to Cleveland, he wanted confirmation that the knee was indeed from a hominid. He took the leg bones to Owen… ([Location 1396](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1396)) - Now that Johanson had an expert’s opinion that his fossil walked upright and therefore really was a hominid, he could focus on his next problem. What kind of hominid walked on these leg bones? Was it a member of the genus Homo, which included humans and their direct ancestors? Or was it the knee of an australopithecine such as those found in South Africa, Kenya, and Tanzania, which some researchers thought were not direct ancestors of modern humans? Before the American and French team could answer those questions, Johanson had a second big find—the partial skeleton known as Lucy. It was a year later, on November 24, 1974, and he was prospecting for fossils again with Tom Gray at Hadar. They were preparing to head back to camp at midday when Johanson decided to check out one last little gully. The first part of Lucy that he spied was a bit of arm bone lying on the ground, partway up a barren slope that had been the shoreline of an ancient lake. Next to it was the back of a small skull, and a few feet away was part of a thighbone. With increasing excitement, Johanson and Gray found vertebrae, part of a pelvis, and ribs. It didn’t take long for them to realize that they were finding parts of a skeleton, which was unheard of at that time. No one had ever found a skeleton of a primitive individual before—and they knew from the preliminary potassium-argon date of the strata where she was found that she had lived about 3 million years ago, although the samples of basaltic rock from a lava flow were badly weathered and yielded dates that were not as reliable as the team’s geologists wanted. (Eventually, new radiometric dates on better samples of potassium-rich volcanic rock would pinpoint Lucy’s age to 3.18 million years.) Gray drove into camp blasting the horn on their Land Rover. Later that afternoon, the entire team fanned out over the gully to collect Lucy’s bones—a task that would take three weeks and yield several hundred pieces of bone. And this time, the entire camp celebrated the discovery, drinking beer and listening to a tape of the Beatles’ song “Lucy in the Sky with Diamonds” blaring over and over all night long. Sometime during that night of celebration, the ancient hominid that was taking shape on a camp table was baptized Lucy. ([Location 1435](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1435)) - In 1974, the same year that Don Johanson found Lucy, a British graduate student named Martin Pickford found a molar that was twice as old as Lucy’s remains. Pickford was mapping the rugged terrain of the Tugen Hills in Kenya as part of his thesis for a Ph.D. in geology. The Tugen Hills are a rare spot in the Great Rift Valley where a giant block of land, called a tilt block, was pushed up to expose layers and layers of ancient sediments. The exposed layers are a time machine for researchers, opening a window into the past from 16 million years ago to modern times—a time span never seen in one place before in the fossil record of Africa. As a result, geologists and paleoanthropologists were drawn to the Tugen Hills for more than a decade before Pickford arrived. The renowned British geologist William Bishop had joined an ambitious project by British geologists to map the terrain in the Tugen Hills and the adjacent valley around Lake Baringo, a muddy brown lake known for its crocodiles, hippos, and hundreds of species of exotic birds. Bishop dispatched two students, including Pickford, to look for fossils in particular. As Pickford traced the contours of ancient sediments across the red hills and dry gullies, he mapped fossils eroding out of the hillsides in more than two hundred places. He wasn’t the first one to find fossils in the area. But one day in 1974, when he spotted a molar in sediments that were about 6 million years old, he recognized it was important. “I always said it was a hominid and it was twice as old as Lucy, but it didn’t make a big impact,” said Pickford. The tooth appeared in Nature. It was a significant accomplishment for a thirty-one-year-old graduate student in geology, but the report written with the paleoanthropologist Peter Andrews from the British Natural History Museum didn’t get much attention in the popular press. It was the oldest known fossil that might have belonged to a hominid, excluding Ramapithecus, which still was a contender for hominid status. But it was found the same year that Don Johanson, also age thirty-one, discovered Lucy. A single molar, no matter how old, was a paltry tidbit compared to a partial skeleton. And without any other bones, it was difficult to prove the molar’s identity as a hominid’s. Some thought it was a hominid tooth. Others thought it belonged to an early chimpanzee or an extinct ape. Regardless of its identity, the molar was interesting because of its promise—it was another scrap of evidence that the ancestors of humans or chimpanzees were indeed living in eastern Africa more than 4 million years ago. It would be years before researchers would find more fossils of hominids in the Tugen Hills. Pickford focused more on the geology for his thesis, and collected thousands of animal fossils between 1975 and 1980. At that point, Pickford wrote a monograph on the animal fossils, but he would say later that he was trying to resist jumping into the “rat race” of finding early hominids. ([Location 1731](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1731)) - The real voyage of discovery consists not in seeking new landscapes but in having new eyes. MARCEL PROUST ([Location 1934](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=1934)) - The tectonic activity is not the only reason the Afar depression is the ideal place for finding fossils. “The cloud deck is important,” says White, as he shows a slide of the Afar visible through banks of clouds. “You have to think about the water that comes when these clouds produce rain.” The water falls down onto the giant dome and into the fissures of the rifts and the low-lying Afar depression. The Afar, like other rift valleys, is a giant basin. Water flowing down rivers, tributaries, and drainage ditches in the rainy season is thick with dirt, rocks, and mud, which get dumped on the low-lying ground at the bottom of rift valley lakes and floodplains. The water and sediment are essential for turning bones into petrified rock, or fossils. If an extinct animal or human ancestor dies on dry land, its carcass is usually devoured by carnivores and its bones weather and decay into dust. But if a hominid is buried quickly and gently by sediments at the shore of a lake or riverbank, for example, it might become the rare creature whose bones fossilize instead of decomposing. Once it’s been buried by fine sediments, there is little oxygen, heat, or moisture to decompose the bones. In ideal circumstances, the bone doesn’t disintegrate, but its organic material, such as DNA and proteins, disappears over time. The remaining spaces or pits in the bone and teeth absorb hard minerals, such as calcium and silica, which percolate slowly into the bone from water in the soil. Over time, the bone fills with hard minerals and becomes petrified, turning into stone. ([Location 2127](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2127)) - While the entire eastern African rift has been called the cradle of mankind, a more apt analogy would be to call it the graveyard for humankind. ([Location 2138](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2138)) - At Aramis, White and WoldeGabriel were lucky enough to find a distinct white ribbon of ash that is the signature of a volcanic eruption 4.4 million years ago, which was laid down directly on top of a layer of salmon-colored sediment that was deposited by floodwaters that filled the basin for decades or even centuries immediately before that eruption—and that is filled with fragmentary fossils. Team members don’t just trust their eyes to trace and map those layers—WoldeGabriel and others take samples of the ancient soil and rock back to their labs in the United States to identify the unique chemical signatures of different sediments of different ages. The glass shards and crystals were formed under intense heat and pressure in different volcanic eruptions, and each has unique chemical fingerprints that help geologists on the team identify and date the different layers of sediment. Using an electron microprobe in their laboratories, they can tease out the ratios of silica, titanium, aluminum, iron, magnesium, and other elements that are the distinct fingerprints of different volcanic eruptions. This identification and naming of different layers of sediment is known as tephrastratigraphy, and is critical for tying fossils to distinct strata of dirt so they can be dated. ([Location 2151](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2151)) - The volcanic crystals in these volcanic horizons, called feldspars, also are packets of data that can be heated with lasers in the lab to release the gases trapped inside. The ratio of two gases in particular—two isotopes of argon—in a single crystal can tell how long ago the feldspar was formed, and so date the volcanic eruption. ([Location 2160](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2160)) - They came from all over the world, from disparate backgrounds—Japanese and Ethiopian students, some from humble origins, working on their hands and knees alongside White and even Ann Getty, the wife of San Francisco billionaire Gordon Getty. At the time, she was a student studying anthropology at Berkeley, where she had taken White’s courses. She and her husband had long been leading donors to the nonprofit organizations that fund anthropological research, but now she could take an active part in the research herself. She and Gordon Getty flew the team from San Francisco to Addis Ababa in their private jet. Ann Getty would contribute more than logistical and financial help to the team and the National Museum of Ethiopia: White is probably the only paleoanthropologist who has thanked the wife of a billionaire in the footnotes of a scientific manuscript for the fieldwork she actually did and for discovering fossils. ([Location 2302](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2302)) - White had just received the delivery of the first set of bones, which were still in their plaster field jackets to protect them for transport, when Meave Leakey came to visit him in Addis Ababa in January 1995. She had casts of the shinbone, jawbone, and teeth from hominids that were alive at Kanapoi 4.1 million years ago. Both White and Leakey were eager to compare the fossils that they had discovered to see if they were the same species—or were closely related. Even Henry Gee had prodded them to get together, writing in his New Year’s piece in Nature that comparisons of the fossils from Ethiopia and Kenya would be necessary to establish whether the fossils represented one species or more, and whether A. ramidus was a hominid. White and Meave Leakey had already planned to meet to compare the corresponding teeth, jaw fragments, and other bones in the two sets of fossils. It quickly became clear, for example, that they were looking at two different types of hominids—and that A. ramidus was more primitive than the fossils from Kanapoi. Leakey and Walker would soon make an announcement about their team’s discoveries at Kanapoi and Allia Bay, a bone bed on the eastern side of Lake Turkana where fragments of teeth and bones would be dated to 3.9 million years old. Later that year, in August 1995, they would describe twenty-two new fossils found at both sites that proved that they had discovered a new type of hominid that was older than Lucy’s species. They named this new hominid Australopithecus anamensis. A shinbone showed that these ape-men or ape-women of the lake had walked upright 3.9 million to 4.1 million years ago. This would be the oldest unambiguous evidence for upright walking in a member of the human family, if indeed the shinbone was as old as they thought. Leakey and Walker also suggested that A. anamensis was the direct ancestor of Lucy’s species, A. afarensis. ([Location 2452](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2452)) - Johanson and his longtime associate paleoanthropologist Bill Kimbel spread out the casts of fossils of A. afarensis on a long conference table, comparing them piece by piece with Meave’s casts. By the end of the session, they agreed they were seeing one long-lasting lineage of early human ancestors that had evolved over time. Such a lineage can include several sequential species, which are known as chronospecies. ([Location 2469](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2469)) - Soon after, White and his colleagues made a move that suggested that A. ramidus was in a class by itself. They had changed their classification at the urging of their colleagues and decided to move the fossils out of Australopithecus, as Gee had predicted, and into a new genus of its own—one they called Ardipithecus, drawing from the Afar word for “ground”; hence, it was now the root ground ape. The new name—Ardipithecus ramidus—would be published in Nature later that year. Where there had been no hominid older than 4 million years, now there were two different genera. ([Location 2472](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2472)) - At sixty-eight, Coppens was white-maned, with droopy eyelids that often look bemused, and a contained manner that gave him an almost courtly presence. One or two people in the café seemed to realize that he was someone worth recognizing, even though they could not quite place him. Indeed, he has been the most famous paleontologist in France for twenty-five years, with as many medals as a war hero—he is a knight of the Legion of Honor, an officer of the National Order of Chad, the recipient of the gold medal of the emperor of Ethiopia, and the beneficiary of two dozen prizes and honors from museums, universities, and corporations in Europe and America. He has published books on human evolution and been a consultant on everything from prehistoric novels to television documentaries. He became France’s leading spokesman on human evolution when he was still in his thirties, soon after he had discovered some of the first fossils of Lucy’s species as part of the international team that worked at Hadar in Ethiopia. But his first big discovery was Yayo. His wife, Françoise Coppens, discovered it in 1961 and named it Tchadanthropus uxoris, which means “my wife’s Chad man.” It was the top part of a skull and face, and the first hominid found in Chad, only two years after Louis and Mary Leakey had found their first hominid fossil—Zinj—in eastern Africa. They found Yayo upside down—as he demonstrated in the café—and did not see its importance until Coppens turned it over and was face-to-face with an early human. Today, he thinks it is a specimen of Homo erectus, a direct ancestor of humans, and it was probably living on the shores of the ancient Lake Chad about 1 million years ago. It would be the only hominid found in Chad for three decades. ([Location 2499](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2499)) - While working in the Omo Valley, Coppens would have plenty of time to reflect on the small number of hominid fossils he and his colleagues were finding compared with the tons of bones of animals, both in Chad and Ethiopia. He would do the math and calculate that for every hominid fossil found at Omo, for example, paleontologists would find ten thousand fossils of extinct animals—a ratio that underscored how vanishingly scarce human ancestors were on the landscape 3 million years ago. Their populations had obviously been small, and hominid bones had never “littered” the landscape. By the early 1980s, researchers had begun to publish their inventories of fossils collected during the rush of expeditions to Africa in the 1960s and 1970s. They had collected two thousand fossils of hominids in eastern Africa in twenty years, ranging from isolated teeth to partial skulls, and hundreds of thousands of fossils of animals. But as rare as hominids were, there was not a single fossil of a chimpanzee or a gorilla in eastern Africa. ([Location 2519](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2519)) - The climate changed, with land on the western side of the rift remaining wet and humid, while the land to the east became hot and dry. The ancestors of apes, such as chimpanzees, stayed in the forests west of the rift zone. All of this was known from the geology. Coppens added this new wrinkle: he proposed that the ancestors of humans began to adapt to their new life in a drier, more open environment. They ventured east into the rift, and those that could adapt to a broader range of habitats were more likely to survive, reinforcing that adaptability in later generations of hominids. This compelling model would explain simply and clearly why chimpanzees and humans were so close genetically, but why the fossils of their ancestors were never found in the same terrain. Coppens called it the East Side Story of human evolution. It was a hypothesis that begged to be tested. All it would take to prove the East Side Story wrong would be to find a fossil of an African ape on the east side of the Great Rift Valley—or a fossil of an early hominid on the west side. ([Location 2540](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2540)) - In France, the tradition has been that paleontology students examine animal fossils first, because they are far more numerous than hominid fossils and better specimens for learning how to work on fossils without damaging them. Their sheer numbers also make it easier to recognize similarities and differences in anatomy within one species, for example, whereas in hominids some species are represented by only a handful of teeth and jaw fragments. ([Location 2572](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2572)) - Brunet worked in the Siwaliks in Pakistan in the early 1980s, just as Pilbeam and his colleagues came to the conclusion that the new fossils of the face of Ramapithecus showed that it was the extinct ape Sivapithecus, not a hominid. This meant that there was no evidence for hominids outside of Africa before 2 million years. It was clear that the search for the earliest ancestors of humans and their closest cousins—the African apes—would have to shift back to Africa. But where should they focus in Africa? Most of Africa was totally unknown to paleoanthropologists. The researchers who had worked in the Siwaliks would continue to focus on slices of time from the Miocene, about 5.3 million to 23.8 million years ago, but in different places in eastern Africa. Pilbeam and Andrew Hill at Yale would start the Baringo basin project in Kenya; Martin Pickford would go to Uganda. Pilbeam would also propose the most radical idea—he would search for the ancestor of African apes in the forests of western Africa. “I’d already figured out it would be important to find fossil chimpanzees,” Pilbeam would recall. “How would you recognize an early hominid if you didn’t have a chimpanzee ancestor for comparison?” Pilbeam studied ecological maps, searching for places where there might have been ancient rain forests. His strategy was to look for the rainy side of volcanoes, where rainwater would have collected to support rain forests—and where there would be volcanic materials to date the sediments. He lighted on Cameroon, which was on the southwestern border of Chad. It was a nation with close ties to France, with its currency tied to the French franc, making it a logical place for French researchers to get funding and logistical help. Even the food and champagne in the part of Cameroon that had been French before independence in 1961 were better than that in the part of the nation that had been British. Pilbeam immediately thought of Brunet, and asked him in the summer of 1981 if he wanted to search for fossils in the formerly French part. Brunet responded enthusiastically, and eventually the two got a field permit to go there in 1984. Many of their colleagues thought they were crazy, because no one ever finds fossils in forests. “We were two young guys. One British, one French. We were crazy,” Brunet would recall. ([Location 2593](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2593)) - It was ironic: Meave Leakey had spent years working at a place—Lothagam—where the fossils were well preserved but where there were probably no hominids. Brunet spent years searching for hominids in precisely the type of forests where apes—and perhaps the earliest hominids—were more likely to have evolved, but where all traces of their bones had vanished. Either way, no fossils of hominids meant no funds. ([Location 2613](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2613)) - As news went around the world of the discovery of an early hominid in Chad, paleoanthropologists outside of the small community of paleontologists who study the origins of mammals were asking, Who is Brunet? It was as if he had come out of nowhere, with the first early hominid outside of eastern Africa and South Africa. “The two windows that were open to us—South Africa and eastern Africa—are only a very small part of the picture,” observed paleoanthropologist Don Johanson, who discovered Lucy. “Brunet had opened a third window.” ([Location 2651](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2651)) - But to say that paleoanthropologists are a highly independent lot is an understatement—many students train through an apprentice system, learning their science and behavior in the lab and field from their individual mentors. As a result, they often forge alliances to their mentors and university, forming intellectual clans that give new meaning to the term “schools of thought.” The notion that paleoanthropologists would voluntarily adopt a code of ethics or formally offer guidance on best practices in the field, in the manner of graduate programs in law or business, was as remote a possibility as getting paleoanthropologists to agree on how to arrange fossils on the human family tree. ([Location 2953](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=2953)) - White would comment later on Haile-Selassie’s uncanny ability to find fossils of hominids, describing it as a talent that has to do with the recognition of three-dimensional shape—a talent that is innate. In an interview with a reporter for the Cleveland Plain Dealer in 2004, he said: Just like playing a piano or pitching a baseball or anything else in life, some people really have that talent and some people don’t. If I gave you a tooth and said what is it, you could tell me it was a tooth but you wouldn’t be able to immediately tell me it’s a rhino tooth. A week later you find another tooth and if you didn’t have these skills, you’d say well maybe it’s a bear, maybe it’s a sloth—I don’t know what the hell it is. But Yohannes would look at it and say, “That’s a rhino tooth.” Right away. It’s this anatomical recognition skill that is absolutely essential in the field, because the fossils that you find aren’t nice intact skulls and jaws. They’re usually broken in very small pieces that are very hard to identify, and you find literally hundreds of thousands of such pieces every day. You’ve got to be able to tell which one’s important and which one’s not. What that means is you’ve got to discriminate the human ancestor among the hundreds of other animal species whose bones and teeth you’re finding scattered across the same outcrop. In fact, Haile-Selassie did not realize how special the jaw fragment was until he was in the lab, analyzing the fossils, almost a year later. As he compared the jaw fragment and four other teeth the team had found, as well as arm and hand bones, with fossils of Lucy’s species and Ardipithecus ramidus, he realized that he had found something even more ancient and apelike. When geochronologist Paul Renne told him that the fossils came from sediments that were 5.8 million years old, based on argon-argon dating, Haile-Selassie knew he had found the remains of the most ancient member of the human family then known—one that was 1.4 million years older than Ardipithecus ramidus, from Aramis. He did not have the right fossils to determine if they were an early form of Ardipithecus ramidus or whether they belonged to some new type of human ancestor. He remembered the controversy that had swirled around Patterson’s partial jawbone found at Lothagam in Kenya three decades earlier and the lessons of initially diagnosing Ramapithecus as a hominid on the basis of a partial jaw fragment. He decided to wait to publish his discovery until after he had more data—in the form of more teeth and bones that would help prove that the fossils were the remains of an ancestor of humans, not chimpanzees. Over the course of the next four years, Haile-Selassie and his colleagues fanned out over the western margin, collecting a total of eleven hominid fossils from five individuals and twenty-five hundred fossils of animals, which underscored that the hominid fossils were just tiny nuggets in an immense landscape littered with pebbles, boulders, and… ([Location 3068](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3068)) - The naming of Orrorin as the earliest known hominid was not the only bold claim in the paper. Pickford and Senut also tried to rewrite early human history by kicking Orrorin’s closest competitors off the direct line leading to humans, starting with Lucy. Even though Orrorin was almost twice as old as Lucy, they wrote in their paper that its thighbone was more like a human’s than those of Lucy and other australopithecines that lived much later—2 million to 4 million years ago. This meant that Orrorin walked in a more modern manner than Lucy did, Senut said. She had drawn a simple phylogenetic diagram showing Orrorin on the direct line to humans. A second line ran parallel to it, leading to Lucy and the other australopithecines and eventually to extinction. A third line repositioned Ardipithecus from Ethiopia right out of the human family. It showed Ardipithecus as the ancestor of African apes instead of humans. It was a hypothesis notable for its simplicity and boldness—and its opposition to the prevailing view of human origins held by most paleoanthropologists. “This simple phylogeny contrasts starkly with mainstream ideas about human evolution, and glosses over many areas of controversy and uncertainty,” wrote paleoanthropologists Leslie Aiello and Mark Collard, then of University College in London, in the journal Nature. It reminded some anthropologists of the view espoused in the 1960s by Louis Leakey, who had also thought that the australopithecines were not directly ancestral to modern humans. Senut, who had earned her Ph.D. studying the arm bones and locomotion of Lucy, had been the main proponent of that view ever since. But unlike Leakey, who would rely on differences in skulls and teeth to sort fossils, Senut reasoned that the skeleton was more reliable for figuring out evolutionary relationships. If bipedalism was the defining trait of being an ancestor of humans rather than African apes, she would look to the bones that had been rearranged to walk upright to identify the direct ancestors of humans. ([Location 3192](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3192)) - The internal architecture of the thighbone shows the history of how the bone was used, because connective tissue is remarkably sensitive to strain. More bone is retained where there is more stress; in other words, the outer layer of the bone is more dense where it needs to be stronger. This is why humans are advised to work out with weights as they age, to prevent the loss of bone density. ([Location 3269](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3269)) - Brunet finally saw the skull a few days after arriving. He described the moment a year later: “It’s a lot of emotion to have in my hand the beginning of the human lineage. I have been looking for this for so long, I knew I would one day find it, so it is a large part of my life too. I’ve been looking for twenty-five years.” Brunet also told the media he was not surprised that Djimdoumalbaye had found it because he was the best fossil hunter on the team. On August 31, Brunet and Beauvilain showed the skull to Chadian president Idriss Déby. Déby spent two hours with them, expressing a deep interest in paleontological work and the areas of the Djurab Desert where they had searched for fossils; he knew the desert well, because he had lived there for many years. Déby kept a delegation waiting for two hours at the airport to go on an official trip to Libya as he examined the skull and talked with Brunet. Before the audience with the skull was over, Brunet suggested that President Déby give a two-syllable name for this ancient member of the human family. After a minute of reflection, President Déby proposed the name Toumaï. He explained that in the Goran language it was a name given to children who were born during the hot, dry season in the desert, when it was most treacherous to be a newborn—thus, Toumaï means “hope of life,” and is supposed to bring babies luck, allowing them to live through difficult times. It was a fitting name for the fossil with great potential, whose offspring would have had to survive difficult times to have given rise to humans. ([Location 3436](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3436)) - Brunet was irritated. Wolpoff and a former student of his, John Hawks of the University of Wisconsin, Madison, had joined Martin Pickford and Brigitte Senut to write a letter to Nature challenging Brunet’s description of Toumaï as a hominid. Senut had told reporters from the day the Nature paper appeared that she thought Toumaï was the female ancestor of gorillas. Now the four had written a letter that was in press in Nature. It would be published the following week, on October 10, 2002, under the title “Sahelanthropus or Sahelpithecus?” The name Sahelpithecus means “ape from the Sahel” as opposed to “human being from the Sahel.” In other words, the four proposed that Toumaï was an ape. They wrote that the features in the teeth, face, and skull used to classify Toumaï as a hominid were not unique to hominids—and could be found in ancient apes. For example, the canine might be small and unsharpened because Toumaï was a female—not a male hominid with a reduced canine. They also measured the length and angle of a plane at the back of the skull where the neck muscles had once attached (based on the photographs in Nature, not the skull) and concluded that it resembled the angle in apes, not hominids. This was significant because it challenged the one bit of indirect evidence that Toumaï might have walked upright. For Brunet, the letter was deeply annoying. In what should have been a moment of triumph, he was facing headlines such as the one in the Observer of London that said, FOSSIL FIND OF THE CENTURY MAY JUST BE A GORILLA AFTER ALL. Brunet’s reply in Nature began with the observation that the Taung baby had also been described as a gorilla when Dart first proposed it as a hominid in 1925—and that any human ancestor alive this close to the split with chimpanzees would, indeed, have many primitive traits. Brunet then pointed out that Wolpoff and his fellow letter writers had measured the angle at the base of the skull incorrectly, failing to take into account that the skull was distorted. The correct angle, minus the effects of being squashed under the weight of sand and rock, put the angle and length within the range expected for early human ancestors, not apes that walked on all fours. Furthermore, he defended the original analysis, saying that the all-important upper canine was diagnostic of being a hominid, because its size and proportion to other teeth fit with human ancestors better than with apes. With a tone of indignation he wrote, “These authors not only misrepresent the specimen’s morphology, but also fail to identify a single character to support their suggestion that Toumaï is a gorilla rather than a hominid ancestor.” Instead, he suggested that they were ignoring the evidence that Toumaï was a hominid in favor of their own “belief ” that Orrorin was a hominid. ([Location 3512](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3512)) - But for the sake of this thought experiment, if the researchers were able to gather every single tooth, jaw fragment, and finger or toe bone they had found that was 4 million years or older—and that had been published between 1994 and 2005—they would bring 144 fossils from Chad, Ethiopia, and Kenya to the summit. If they were really in a munificent mood and brought along unpublished fossils, the number would soar to include the bones of two partial skeletons from Ethiopia: the crushed partial skeleton of Ardipithecus ramidus being analyzed by White and his colleagues and a new partial skeleton of an upright-walking hominid that was nearly 4 million years old and had been discovered in February 2005 by Yohannes Haile-Selassie in Ethiopia. Two other teams working in Ethiopia, including those of Ethiopian Sileshi Semaw and Austrian Horst Seidler, have also found new fossils of Ardipithecus that should fill in some gaps for that species. Even though most of the published fossils are teeth and jaw fragments, it is an impressive collection by any standard. Before 1992, only a half dozen fossils of hominids older than 4 million years were known. Together, the fossils collected in the 1990s and early 2000s would cover a large desk and would represent a few dozen individuals at least. This is the hard data (along with younger fossils) that the field of paleoanthropology is built upon. In a proposal for funding to the National Science Foundation in 2003, Berkeley paleoanthropologist Clark Howell and White wrote, “These dramatic discoveries promise to finally answer questions that have been a central focus of human origins studies for over a century: when, where, how, and why hominids originated from the last common ancestor they shared with chimpanzees.” ([Location 3676](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3676)) - Although paleoanthropologists are asking many questions of these fossils, they are just beginning to get answers about their place in nature. The when and where are clearly coming into focus: when was more than 6 million years ago, possibly 7 or 8 million years if the oldest fossils on the table prove to be the earliest members of the human family. This means that paleoanthropologists can now see back in time twice as far as they could before the discoveries of the past decade. The new fossils have also meant that the fossil record is finally in sync with the molecular clock, which for thirty years has timed the split of chimpanzees and humans to sometime in the past 4 million to 6 million years—a range revised recently to 5 million to 7 million years. The where is clearly Africa, which has been widely accepted as the birthplace of the human family since the discovery of Lucy’s species in the mid-1970s. But what is new is that the fossil record is exclusively African for almost five million years, since no hominids older than 1.8 million years have been detected outside of Africa. These new fossils at the dawn of humanity are a dramatic confirmation of Darwin’s tentative proposal in 1871 that “it is somewhat more probable that our early progenitors lived on the African continent than elsewhere.” But who among the fossils on the table is the oldest known progenitor of humans? If Brunet were to bring to the fossil summit the stunning skull of Toumaï and the jawbones and teeth of other members of Sahelanthropus tchadensis that were alive 6 million to 7 million years ago in Chad, would everyone assembled agree that it was the earliest known hominid, as he and his many coauthors have asserted? The problem is that there is still no consensus on how to define a member of the human family this ancient. There are no fossils of chimpanzees or gorillas—other than some isolated teeth—to show paleoanthropologists what the ancestors of the African apes looked like 5 million to 7 million years ago. Even though Toumaï and all of the other fossils on the table have been proposed as hominids, they were alive so close to the split with chimpanzees that they look more like the ancient ape ancestor they shared with chimpanzees than their human descendants. As White told the well-known radio talk-show host Terry Gross on National Public Radio’s Fresh Air: “You wouldn’t invite Ardipithecus ramidus to dinner.” ([Location 3688](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3688)) - Even if most of the researchers at the fossil summit could agree on which fossil was the earliest known member of the human family, they also would face the even thornier problem of figuring out how many different types of hominids were lying on that table. One reason for the confusion is that, other than teeth, there is little overlap in the skeletal parts to compare. Brunet has a skull, but no one else does, excluding White’s unpublished crushed skull of Ardipithecus ramidus. Pickford and Senut have a thighbone of Orrorin, but it is not connected to a toe bone, which is what Haile-Selassie has for Ardipithecus kadabba, while Meave Leakey and Alan Walker have a shinbone and a wrist bone for Australopithecus anamensis—and so on. For now, they will have to stick to the teeth and jaw fragments for direct comparisons between these early hominids—at least until White and his colleagues bring a raft of brittle bones to the table when he publishes the reconstruction of the partial skeleton and squashed skull of Ardipithecus ramidus. White has proposed this skeleton as a Rosetta stone that will reveal the anatomic code for upright walking in early hominids. By looking at the way the torso, pelvis, and limb bones fit together, researchers should be able to see the way Ardipithecus’s body adapted to its movements, both on the ground and in the trees. A key question that White and others are asking of this skeleton, for example, is whether the anatomy for upright walking was already fully assembled in Ardipithecus at 4.4 million years, as it appears to have been in its proposed descendant, Australopithecus anamensis, at 4 million years. “If we had skeletons of Sahelanthropus, Orrorin, and Ardipithecus, we’d be able to see the evolution of bipedalism,” says locomotion expert Owen Lovejoy, who is part of the Middle Awash team analyzing the skeleton of Ardipithecus ramidus. ([Location 3722](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3722)) - The new fossils have clearly opened new windows into the past, in time and space, offering a view for the first time of the earliest stages of human evolution in central Africa, as well as in eastern Africa and South Africa. But when different paleoanthropologists look through those windows, they do not see the same thing. On the one hand, Tim White and Brunet see Toumaï as a close relative of Ardipithecus, which in turn gave rise to the australopithecines and early Homo. Orrorin may also be a member of Ardipithecus, in White’s and Haile-Selassie’s view. Pickford and Senut have rejected that and nominate Orrorin, instead, as the ancestor of humans, Ardipithecus as the ancestor of chimpanzees, and Sahelanthropus as the ancestor of gorillas or some extinct ape. ([Location 3736](https://readwise.io/to_kindle?action=open&asin=B000GCFWGY&location=3736))