GREAT SCIENTISTS AND PALEONTOLOGISTS IN THE STUDY OF OUR HUMAN ANCESTORS

FAMOUS PALEONTOLOGISTS AND EVOLUTIONARY SCIENTISTS

Don Johanson and Lucy

Famous hominid scientists include the Leakeys family (See Separate Article) and Donald Johanson, the discoverer of Lucy and now director of the Institute of Human Origins at Arizona State University. Tim White, a paleoanthropologist at the University of California, Berkeley, who was in on the Lucy discovery when he was only 28, is one of the most quoted scientists in the hominid field today.

Edward O. Wilson (born 1929) is not a paleontologist, archaeologist, anthropologist or a geneticist but as the founder of sociobiology and a determined thinker he has made many contributions to ideas about evolution. Colin Woodard wrote in the Washington Post: Wilson “is a giant of science: the world’s leading expert on ants, the first researcher to recognize the existence of pheromones, the father of sociobiology, the author and co-author of two Pulitzer Prize-winning books (“On Human Nature” and “The Ants”) and a recipient of the Royal Swedish Academy’s Crafoord Prize, given in fields not covered by the Nobel Prize.

“A professor emeritus at Harvard, he has produced a body of work that has withstood scientific critics, including those who rejected his assertion that both animal and human social behavior is based on biological and evolutionary principles. (Activists dumped a pitcher of ice water on him during a 1978 meeting of the American Association for the Advancement of Science.) Others rejected his prediction in “The Diversity of Life” (1992) that more than a quarter of all species on Earth would vanish by mid-century, but subsequent research has supported the notion that we are in the midst of the Earth’s sixth great extinction. [Source: Colin Woodard, Washington Post, April 13, 2012]

Among contemporary paleontologists and anthropologists Rick Potts stands out. He argues that environmental instability and disruption were decisive factors in the success of Homo sapiens: Alone among our primate tribe, we were able to cope with constant change and turn it to our advantage. Potts is director of the Smithsonian Institution’s Human Origins Program, curator of anthropology at the National Museum of Natural History in Washington, D.C., and curator of the David H. Koch Hall of Human Origins, which opened at that museum last year. He also leads excavations in the East African Rift Valley and codirects projects in China that compare early human behavior and environments in eastern Africa with those in eastern Asia. Here Potts explains the reasoning behind his controversial idea.

Websites and Resources on Hominins and Human Origins: Smithsonian Human Origins Program humanorigins.si.edu ; Institute of Human Origins iho.asu.edu ; Becoming Human University of Arizona site becominghuman.org ; Talk Origins Index talkorigins.org/origins ; Last updated 2006. Hall of Human Origins American Museum of Natural History amnh.org/exhibitions ; Wikipedia article on Human Evolution Wikipedia ; Human Evolution Images evolution-textbook.org; Hominin Species talkorigins.org ; Paleoanthropology Links talkorigins.org ; Britannica Human Evolution britannica.com ; Human Evolution handprint.com ; National Geographic Map of Human Migrations genographic.nationalgeographic.com ; Humin Origins Washington State University wsu.edu/gened/learn-modules ; University of California Museum of Anthropology ucmp.berkeley.edu; BBC The evolution of man" bbc.co.uk/sn/prehistoric_life; "Bones, Stones and Genes: The Origin of Modern Humans" (Video lecture series). Howard Hughes Medical Institute.; Human Evolution Timeline ArchaeologyInfo.com ; Walking with Cavemen (BBC) bbc.co.uk/sn/prehistoric_life ; PBS Evolution: Humans pbs.org/wgbh/evolution/humans; PBS: Human Evolution Library www.pbs.org/wgbh/evolution/library; Human Evolution: you try it, from PBS pbs.org/wgbh/aso/tryit/evolution; John Hawks' Anthropology Weblog johnhawks.net/ ; New Scientist: Human Evolution newscientist.com/article-topic/human-evolution; Fossil Sites and Organizations: The Paleoanthropology Society paleoanthro.org; Institute of Human Origins (Don Johanson's organization) iho.asu.edu/; The Leakey Foundation leakeyfoundation.org; The Stone Age Institute stoneageinstitute.org; The Bradshaw Foundation bradshawfoundation.com ; Turkana Basin Institute turkanabasin.org; Koobi Fora Research Project kfrp.com; Maropeng Cradle of Humankind, South Africa maropeng.co.za ; Blombus Cave Project web.archive.org/web; Journals: Journal of Human Evolution journals.elsevier.com/; American Journal of Physical Anthropology onlinelibrary.wiley.com; Evolutionary Anthropology onlinelibrary.wiley.com; Comptes Rendus Palevol journals.elsevier.com/ ; PaleoAnthropology paleoanthro.org.

Quest for the Origins of Human Life in Africa

Raymond Dart

In a review of the book “Born in Africa: The Quest for the Origins of Human Life” by Martin Meredith, Rachel Newcomb wrote in the Washington Post, “In 1924, anatomy professor Raymond Dart came across an unusual skull that a mining company had inadvertently blasted out of a hillside in a South African village. Despite its small brain size, the Taung Child, as the skull was to be named, had distinctively human features, including signs that its owner walked upright. But Dart's finding contradicted prevailing scientific opinion, which held that the evolution of a large brain preceded other human adaptations, such as walking. Confirming this belief was the 1912 discovery of Piltdown Man, a skull found in a gravel pit in Piltdown, England. With its large cranium but otherwise apelike features, Piltdown Man supposedly represented the missing link between primates and humans, proving that humans came out of Asia and not Africa. [Source: Rachel Newcomb, Washington Post, July 14 2011 ***]

“Dart disagreed, and he enthusiastically published his findings. Yet the conservative scientific establishment savaged him, arguing that he had misidentified a mere primate. Among Dart's other crimes were failing to follow proper research protocol and using “a “barbarous” combination of Latin and Greek in naming the specimen Australopithecus." After this professional drubbing, Dart suffered a nervous breakdown, and the Taung skull languished for years as a paperweight on the desk of a colleague. ***

“Twenty-three years later, Robert Broom, a maverick fossil hunter and physician who conducted his South African excavations under the blazing sun dressed “in a dark suit and waistcoat, long-sleeved white shirt, stiff butterfly collar and somber tie," made his own discovery of an australopithecine, finally vindicating Dart. In 1953, scientists confirmed that Piltdown Man had been an elaborate 40-year hoax, a skull patched together from a combination of human and orangutan remains and artificially distressed to appear ancient. The Piltdown skull was only a few hundred years old; the Taung Child, however, was eventually dated at 2.7 million years. Broom's discoveries finally turned the tide of scientific opinion toward accepting humanity's origins in Africa. ***

“In Tanzania's Olduvai Gorge, where Mary Leakey first spotted the 1.75 million-year-old skull she referred to affectionately as “Dear Boy," researchers battled black dust clouds, drought conditions and incessant sun while also having “to contend with marauding lions, rhinoceroses and hyenas." Later, Richard Leakey's team found a 1.6 million-year-old, nearly complete skeleton in Kenya's Lake Turkana, which “resembled a lunar landscape, a boundless expanse of lava and sand littered with the wrecks of ancient volcanoes. The winds and the heat were ferocious." ***

“Fossil hunting was an arduous and frequently unrewarding business. Sometimes years would pass with no discoveries at all as researchers scrambled to acquire funding and government permits. Although Meredith gives credit to native fossil hunters who unearthed noteworthy finds, the scientists, many of whom were skilled at self-promotion, take center stage. At the start of new fieldwork in Koobi Fora, Kenya, for example, Richard Leakey, “with romantic notions of himself as a heroic explorer riding across the African desert," hired camels and let the cameras roll. In 1974, when Leakey's American rival Donald Johanson announced his discovery of the 3.2 million-year-old australopithecine known as Lucy, he shouted on camera, “I've got you now, Richard!” Outsized personalities, turf wars, public insults and heated debates were the order of the day.” ***

Book: “Born in Africa: The Quest for the Origins of Human Life” by Martin Meredith (PublicAffairs, 2011]

Eugene DuBois and the Discovery of Java Man

Eugene DuBois

Java man was discovered by Eugene DuBois, a young Dutch military doctor, who came to Java in 1887 with the sole purpose of finding the "missing link" between humans and apes after hearing about discoveries of ancient human bones (which later turned out to belong to modern humans) near the Javanese village of Wajak, near Tulung Agung, in eastern Java.

With the help of 50 East Indian convict laborers, he discovered a skull cap and thighbone — that clearly didn't belong to an ape — along the banks of the Sunngai Bengawan Solo River in 1891. After measuring the cranial capacity of the skull with mustard seeds, Dubois realized that the creature was more of an "ape-like man" than a "man-like ape." Dubois dubbed the find Pithecanthropus erectus , or "upright ape-man," which is now regarded as an example of Homo erectus .

The discovery of Java Man was the first major hominid find, and helped launch the study of early man. His finding created such a storm of controversy that Dubois felt compelled to re-bury the bones for 30 years to protect them.

DuBois was the student of Ernst Haeckel, a Charles Darwin disciple who wrote History of Natural Creation (1947), which advocated the Darwinian view of evolution and speculated about primitive human beings. Dubois came to Indonesia with the ambition of confirming Haekel's theories. He died a bitter man because his discoveries he felt weren't taken seriously.

After Dubois other Homo erectus bones were unearthed in Java. In the 1930s, Ralph von Koenigswald found fossils, dated at be 1 million years old, near the village of Sangiran, along the Solo river, 15 kilometers north of Solo. Other fossils have been found along the Sungai Bengawan Solo in Central and East Java and near Pacitan in East Java's south coast. In 1936 a skull of a child was found at Perning neat Mojokerto.

Raymond Dart and the Discovery of the Taung Child

The Taung Child fossil was found in 1924 by a mine worker excavating for lime after it had been inadvertently blasted out of a hillside in a South African village.He gave the skull to his boss who in turn gave it to Professor Raymond Dart at the University of Witwatersand in Johannesburg, the story goes, hours before he was to be the best man at his best friend's wedding.

Anxiously he went through the motions at wedding and afterwards rushed home where he used one his wife's knitting needles to clean the fossil. He knew he had made a great discovery and when he published his findings in the journal Nature he became an instant celebrity at the age of 32. Other hominid skulls had been discovered before this but none that were this old. [Source: Kenneth Weaver, National Geographic, November 1985]

Dart coined the term Australopithecus ("southern ape"), a reference to the fact that the first Australopithecus fossils were found in southern Africa. Australopithecus africanus means "southern ape of Africa." Various pieces of evidence convinced Dart that the the fossil child was a bipedal human ancestor, a transitional form between apes and humans. According to one story he announced at a dinner in his honor, "Darwin's evolution of man was just a theory. I, Raymond Dart, have proved it!" and then burst into tears.

Marcellin Boule and Out Misconceptions About Neanderthals

Marcellin Boule

Our image of Neanderthals as "dim-witted brutes" originally came from Marcellin Boule, a French authority on fossils who reconstructed a near complete skeleton found in southwestern France, and claimed it had "prehensile feet, could not fully extend his legs, and thrust his head awkwardly forward because his spine prevented him from standing upright." In his scientific paper he described the "brutish appearance of this muscular and clumsy body."

Jon Mooallemjan wrote in the New York Times magazine: “One of the earliest authorities on Neanderthals was a Frenchman named Marcellin Boule. A lot of what he said was wrong. In 1911, Boule began publishing his analysis of the first nearly complete Neanderthal skeleton ever discovered, which he named Old Man of La Chapelle, after the limestone cave where it was found. Laboring to reconstruct the Old Man’s anatomy, he deduced that its head must have been slouched forward, its spine hunched and its toes spread like an ape’s. Then, having reassembled the Neanderthal this way, Boule insulted it. This “brutish” and “clumsy” posture, he wrote, clearly indicated a lack of morals and a lifestyle dominated by “functions of a purely vegetative or bestial kind.” A colleague of Boule’s went further, claiming that Neanderthals usually walked on all fours and never laughed: “Man-ape had no smile.” Boule was part of a movement trying to reconcile natural selection with religion; by portraying Neanderthals as closer to animals than to us, he could protect the ideal of a separate, immaculate human lineage. When he consulted with an artist to make a rendering of the Neanderthal, it came out looking like a furry, mean gorilla. [Source: Jon Mooallemjan, New York Times magazine, January 11, 2017 ||*||]

“Neanderthal fossils kept surfacing in Europe, and scholars like Boule were scrambling to make sense of them, improvising what would later grow into a new interdisciplinary field, now known as paleoanthropology. The evolution of that science was haphazard and often comically unscientific. An exhaustive history by Erik Trinkaus and Pat Shipman describes how Neanderthals became “mirrors that reflected, in all their awfulness and awesomeness, the nature and humanity of those who touched them.” That included a lot of human blundering. It became clear only in 1957, for example — 46 years after Boule, and after several re-examinations of the Old Man’s skeleton — that Boule’s particular Neanderthal, which led him to imagine all Neanderthals as stooped-over oafs, actually just had several deforming injuries and severe osteoarthritis. ||*||

“Still, Boule’s influence was long-lasting. Over the years, his ideologically tainted image of Neanderthals was often refracted through the lens of other ideologies, occasionally racist ones. In 1930, the prominent British anthropologist Sir Arthur Keith, writing in The New York Times, channeled Boule’s work to justify colonialism. For Keith, the replacement of an ancient, inferior species like Neanderthals by newer, heartier Homo sapiens proved that Britain’s actions in Australia — “The white man ... replacing the most ancient type of brown man known to us” — was part of a natural order that had been operating for millenniums.” ||*||

Lee Berger

Lee Berger

Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg, has made some of the most headline-grabbing finds in recent years, including the discoveries of Australopithecus sediba and Homo naledi. Jamie Shreeve wrote in National Geographic: Berger “is a big-boned American with a high forehead, a flushed face, and cheeks that flare out broadly when he smiles, which is a lot of the time. His unquenchable optimism has proved essential to his professional life. By the early 1990s, when Berger got a job at the University of the Witwatersrand (“Wits”) and had begun to hunt for fossils, the spotlight in human evolution had long since shifted to the Great Rift Valley of East Africa. [Source:Jamie Shreeve, National Geographic, September 2015 /+]

“Most researchers regarded South Africa as an interesting sidebar to the story of human evolution but not the main plot. Berger was determined to prove them wrong. But for almost 20 years, the relatively insignificant finds he made seemed only to underscore how little South Africa had left to offer. What he most wanted to find were fossils that could shed light on the primary outstanding mystery in human evolution: the origin of our genus, Homo, between two million and three million years ago. On the far side of that divide are the apelike australopithecines, epitomized by Australopithecus afarensis and its most famous representative, Lucy, a skeleton discovered in Ethiopia in 1974. On the near side is Homo erectus, a tool-wielding, fire-making, globe-trotting species with a big brain and body proportions much like ours. Within that murky million-year gap, a bipedal animal was transformed into a nascent human being, a creature not just adapted to its environment but able to apply its mind to master it. How did that revolution happen?/+\

In August 2014, Berger traveled to East Africa. To mark the occasion of Louis Leakey's description of H. habilis, Richard Leakey had summoned the leading thinkers on early human evolution to a symposium at the Turkana Basin Institute.... Some of Lee Berger’s harshest critics would be there, including some who’d written scathing reviews of his interpretation of the A. sediba fossils. To them, he was an outsider at best, a hype artist at worst. Some threatened not to attend if he were there. But given the Rising Star discovery, Leakey could hardly not invite him. “There’s no one on Earth finding fossils like Lee is now,” Leakey said.” /+\

During much of the meeting Berger “was uncommonly subdued, adding little to the discussion, until the topic turned to a comparison of A. sediba and H. habilis. It was time. “More of interest perhaps to this debate is Rising Star,” he offered. For the next 20 minutes he laid out all that had happened—the serendipitous discovery of the cave, the crash analysis in June, and the gist of its findings. While he talked, a couple of casts of Rising Star skulls were passed hand to hand./+\

“Then came the questions. Have you done a cranio-dental analysis? Yes. The H. naledi skull and teeth place it in a group with Homo erectus, Neanderthals, and modern humans. Closer to H. erectus than H. habilis is? Yes. Are there any tooth marks on the bones from carnivores? No, these are the healthiest dead individuals you’ll ever see. Have you made progress on the dating? Not yet. We’ll get a date sometime. Don’t worry. Then, when the questions were over, the gathered doyens did something no one expected, least of all Berger. They applauded.” /+\

Svante Pääbo

Jamie Shreeve wrote in National Geographic: “Pääbo grew up in Stockholm with his single mother, a chemist, and on certain days with his father, a biochemist named Sune Bergström, who had another, legitimate family and would later win a Nobel Prize. Pääbo’s own first passion was Egyptology, but he switched to molecular biology, then fused the two interests in 1984 with his work on mummy DNA. Once anchored in the study of the past, he never let go. He is 58 now, tall and lanky, with large ears, a long, narrow head, and pronounced eyebrows that arch up and down animatedly when he’s excited—about Denisova, for instance.” [Source: Jamie Shreeve, National Geographic, July 2013 +]

20120201-svante paabo.jpg
Svante Paabo Svante Paabo, a Swede who heads of the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, has been at the center of a lot of recent discoveries in study of the DNA of early man and his ancestors. In 2006, his team announced they had decoded fragments of Neanderthal DNA. The team has also uncovered how closely related humans are despite their outward appearances and has found key genetic markers that were crucial in the development of ancient man, including one, FOXP2, that played an important role in the development of the brain and language in modern humans 200,000 years ago.

Paabo grew up in Sweden fascinated by ancient cultures and archaeology, When he was 13, his mother, a food chemist in Stockholm, fulfilled her son’s wish and took him to Egypt to see the pyramids, Karnak and the Valley of the Kings. In 1975, he entered the University of Uppsala to study Egyptology but soon tired of the way it was taught with its emphasis understanding the grammar of the ancient Egyptian language rather that embarking on archaeological digs. He then found himself in medical school and became a biochemist like his Dad. While working on his Ph.D. in molecular immunology he took samples from mummies and tried to see if he could extract some DNA from them. He was able to get some from a 2,400-year-old mummy of an infant boy, with the discovery making the cover of the journal Nature before he even finished his PhD.

In the 1980s and 1990s Paabo was involve in unraveling the DNA is in ancient animals such as moas, mammoths and marsupial wolves, He also was part of the team that sequenced some DNA from the “Iceman” frozen in a glacier in the Alps. In 1997 he was invited by the German government to Leipzig to launch the Max Planck Institute of Evolutionary Anthropology, whose central aim of finding out “what makes human beings unique.”

In May 2010, the team lead by Paabo reported they had come along way sequencing the Neanderthal genome and among the discoveries they had made were that humans and Neanderthals mated and as a result of this union between 1 percent and 4 percent of the genes in people from Europe and Asia trace back to Neanderthals.

The research was published online in the journal Nature in March 2010 by Johannes Krause and Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzing, Germany. The work decoded the complete set of DNA from mitochondria. If the research does hold up it suggest a migration out of Africa around 1 million years ago. Scientists are now low looking for similarities between the DNA of the Siberian ancestor and that of Neanderthal. Neanderthals, Homo erectus and homo heidelbergensis.

Svante Pääbo’s Early Life

Pääbo was born in 1955. Elizabeth Kolbert wrote in The New Yorker: He “grew up in Stockholm. His mother, a chemist, was an Estonian refugee. For a time, she worked in the laboratory of a biochemist named Sune Bergström, who later won a Nobel Prize. Pääbo was the product of a lab affair between the two, and, although he knew who his father was, he wasn’t supposed to discuss it. Bergström had a wife and another son; Pääbo’s mother, meanwhile, never married. [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011 ]

Every Saturday, Bergström would visit Pääbo and take him for a walk in the woods, or somewhere else where he didn’t think he’d be recognized. “Officially, at home, he worked on Saturday,” Pääbo told me. “It was really crazy. His wife knew. But they never talked about it. She never tried to call him at work on Saturdays.” As a child, Pääbo wasn’t particularly bothered by the whole arrangement; later, he occasionally threatened to knock on Bergström’s door. “I would say, ‘You have to tell your son—your other son—because he will find out sometime,’ ” he recalled. Bergström would promise to do this, but never followed through. (As a result, Bergström’s other son did not learn that Pääbo existed until shortly before Bergström’s death, in 2004.)

“From an early age, Pääbo was interested in old things. He discovered that around fallen trees it was sometimes possible to find bits of pottery made by prehistoric Swedes, and he filled his room with potsherds. When he was a teen-ager, his mother took him to visit the Pyramids, and he was entranced. He enrolled at Uppsala University, planning to become an Egyptologist. “I really wanted to discover mummies, like Indiana Jones,” he said. Mostly, though, the coursework turned out to involve parsing hieroglyphics, and instead of finding it swashbuckling Pääbo thought it was boring. Inspired by his father, he switched first to medicine, then to cell biology.”

Svante Pääbo’s Early Career

Elizabeth Kolbert wrote in The New Yorker: “In the early nineteen-eighties, Pääbo was doing doctoral research on viruses when he once again began fantasizing about mummies. At least as far as he could tell, no one had ever tried to obtain DNA from an ancient corpse. It occurred to him that if this was possible, then a whole new way of studying history would open up. [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011 ]

“Suspecting that his dissertation adviser would find the idea silly (or worse), Pääbo conducted his mummy research in secret, at night. With the help of one of his former Egyptology professors, he managed to obtain some samples from the Egyptian Museum in what was then East Berlin. In 1984, he published his results in an obscure East German journal. He had, he wrote, been able to detect DNA in the cells of a mummified child who’d been dead for more than two thousand years. Among the questions that Pääbo thought mummy DNA could answer were what caused pharaonic dynasties to change and who Tutankhamun’s mom was.

“While Pääbo was preparing a version of his mummy paper for publication in English, a group of scientists from the University of California at Berkeley announced that they had succeeded in sequencing a snippet of DNA from a zebralike animal known as a quagga, which had been hunted to extinction in the eighteen-eighties. (The DNA came from a hundred-and-forty-year-old quagga hide preserved at the National History Museum in Mainz.) The leader of the team, Allan Wilson, was an eminent biochemist who had, among other things, come up with a way to study evolution using the concept of a “molecular clock.” Pääbo sent Wilson the galleys of his mummy paper. Impressed, Wilson replied asking if there was any space in Pääbo’s lab; he might like to spend a sabbatical there. Pääbo had to write back that he could not offer Wilson space in his lab, because, regrettably, he didn’t have a lab—or even, at that point, a Ph.D.

“Pääbo’s mummy paper became the cover article in Nature. It was also written up in the Times, which called his achievement “the most dramatic of a series of recent accomplishments using molecular biology.” Pääbo’s colleagues in Sweden, though, remained skeptical. They urged him to forget about shrivelled corpses and stick to viruses. “Everybody told me that it was really stupid to leave that important area for something which looked like a hobby of some sort,” he said. Ignoring them, Pääbo moved to Berkeley, to work for Wilson.

“While Pääbo was living in California, he sometimes went to Germany to visit a woman who was attending graduate school at the University of Munich. “I had many relationships with men, but I also had girlfriends now and again,” he told me. The relationship ended; shortly afterward, the University of Munich offered Pääbo an assistant professorship. With no pressing reason to move to Germany, he demurred. The offer was increased to a full professorship: “So then I said, ‘Germany isn’t that bad after all. I’ll go there for a few years.’ ”
““He just kind of glided in,” Mary-Claire King, who had also been a student of Wilson’s, and who is now a professor of genome sciences at the University of Washington, recalled. According to King, Pääbo and Wilson, who died in 1991, turned out to share much more than an interest in ancient DNA. “Each of them thought of very big ideas,” she told me. “And each of them was very good at translating those ideas into testable hypotheses. And then each of them was very good at developing the technology that’s necessary to test the hypotheses. And to have all three of those capacities is really remarkable.” Also, although “they were both very data-driven, neither was afraid to say outrageous things about their data, and neither was afraid to be wrong.”“

Svante Pääbo and Neanderthal and Denisovan DNA

Elizabeth Kolbert wrote in The New Yorker: “Pääbo’s most ambitious project to date, which he has assembled an international consortium to assist him with, is an attempt to sequence the entire genome of the Neanderthal. The project is about halfway complete and has already yielded some unsettling results, including the news, announced by Pääbo last year, that modern humans, before doing in the Neanderthals, must have interbred with them. [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011 ]

“Once the Neanderthal genome is complete, scientists will be able to lay it gene by gene—indeed, base by base—against the human, and see where they diverge. At that point, Pääbo believes, an answer to the age-old question will finally be at hand. Neanderthals were very closely related to modern humans—so closely that we shared our prehistoric beds with them—and yet clearly they were not humans. Somewhere among the genetic disparities must lie the mutation or, more probably, mutations that define us. Pääbo already has a team scanning the two genomes, drawing up lists of likely candidates. “I want to know what changed in fully modern humans, compared with Neanderthals, that made a difference,” he said. “What made it possible for us to build up these enormous societies, and spread around the globe, and develop the technology that I think no one can doubt is unique to humans. There has to be a genetic basis for that, and it is hiding somewhere in these lists.”

Jamie Shreeve wrote in National Geographic: “The Neanderthal DNA he had made headlines with in 1997 was utterly different from that of any person now alive on Earth. It seemed to suggest that Neanderthals had been a separate species from us that had gone extinct—suspiciously soon after our ancestors first migrated out of Africa into the Neanderthals’ range in western Asia and Europe. But that DNA, like Krause’s first extract from the Denisovan finger, was mtDNA: It came from the mitochondria, the energy-producing organelles inside the cell, and not from the cell nucleus, where the vast bulk of our genome resides. Mitochondrial DNA includes only 37 genes, and it’s inherited only from the mother. It’s a limited record of a population’s history, like a single page torn from a book. [Source: Jamie Shreeve, National Geographic, July 2013 +]

“By the time of the Denisova symposium, Pääbo and his colleagues had published first drafts of the entire Neanderthal and Denisovan genomes. Reading so many more pages allowed Pääbo and his colleagues, including David Reich at Harvard University and Montgomery Slatkin at the University of California, Berkeley, to discover that human genomes today actually contain a small but significant amount of Neanderthal code—on average about 2.5 percent. The Neanderthals still may have been swept into extinction by the strange, high-browed new people who followed them out of Africa, but not before some commingling that left a little Neanderthal in most of us, 50,000 years later. Only one group of modern humans escaped that influence: Africans, because the commingling happened outside that continent.” +\

Svante Pääbo at Work

Elizabeth Kolbert wrote in The New Yorker: “Svante Pääbo heads the institute’s department of evolutionary genetics. He is tall and lanky, with a long face, a narrow chin, and bushy eyebrows, which he often raises to emphasize some sort of irony. Pääbo’s office is dominated by a life-size model of a Neanderthal skeleton, propped up so that its feet dangle over the floor, and by a larger-than-life-size portrait that his graduate students presented to him on his fiftieth birthday. Each of the students painted a piece of the portrait, the over-all effect of which is a surprisingly good likeness of Pääbo, but in mismatched colors that make it look as if he had a skin disease. [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011 ]

“At any given moment, Pääbo has at least half a dozen research efforts in progress. When I visited him in May, he had one team analyzing DNA that had been obtained from a forty- or fifty-thousand-year-old finger bone found in Siberia, and another trying to extract DNA from a cache of equally ancient bones from China. A third team was slicing open the brains of mice that had been genetically engineered to produce a human protein. In Pääbo’s mind, at least, these research efforts all hang together. They are attempts to solve a single problem in evolutionary genetics, which might, rather dizzyingly, be posed as: What made us the sort of animal that could create a transgenic mouse? The question of what defines the human has, of course, been kicking around since Socrates, and probably a lot longer. If it has yet to be satisfactorily resolved, then this, Pääbo suspects, is because it has never been properly framed. “The challenge is to address the questions that are answerable,” he told me.

“One afternoon, when I wandered into his office, Pääbo showed me a photograph of a skullcap that had recently been discovered by an amateur collector about half an hour from Leipzig. From the photograph, which had been e-mailed to him, Pääbo had decided that the skullcap could be quite ancient—from an early Neanderthal, or even a Homo heidelbergensis. He’d also decided that he had to have it. The skullcap had been found at a quarry in a pool of water—perhaps, he theorized, these conditions had preserved it, so that if he got to it soon, he’d be able to extract some DNA. But the skull had already been promised to a professor of anthropology in Mainz. How could he persuade the professor to give him enough bone to test? [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011 ]

“Pääbo called everyone he knew who he thought might know the professor. He had his secretary contact the professor’s secretary to get the professor’s private cell-phone number, and joked—or maybe only half joked—that he’d be willing to sleep with the professor if that would help. The frenzy of phoning back and forth across Germany lasted for more than an hour and a half, until Pääbo finally talked to one of the researchers in his own lab. The researcher had seen the actual skullcap and concluded that it probably wasn’t very old at all. Pääbo immediately lost interest in it.

“With old bones, you never really know what you’re going to get. A few years ago, Pääbo managed to get hold of a bit of tooth from one of the so-called “hobbit” skeletons found on the island of Flores, in Indonesia. (The “hobbits,” who were discovered in 2004, are generally believed to have been diminutive archaic humans—Homo floresiensis—though some scientists have argued that they were just modern humans who suffered from microcephaly.) The tooth, which was about seventeen thousand years old, yielded no DNA.”

David Reich

David Reich is Harvard University geneticist who has also had his attached to many important discoveries regarding the DNA of Neanderthals, Denisovans and other ancestors of people living today. Robin McKie wrote in The Guardian: “Reich’s work as a leader of prehistoric population studies includes the discovery that all people of non-African descent carry small amounts of Neanderthal DNA, showing that Homo sapiens – at one stage – must have interbred with this long-dead species of ancient humans. Reich was also involved in uncovering the existence of Denisovans, a previously unknown species of ancient humans, using DNA found in fossil scraps in a Siberian cave. In addition, he has discovered that 5,000 years ago northern Europe was overrun by invaders from central Asia, a migration of profound importance – for those newcomers became the first people of the British Isles. [Source: Robin McKie, The Guardian, April 7, 2018]

“These remarkable recreations of our past are outlined in Reich’s book “Who We Are and How We Got Here,” in which he chronicles the spectacular rise of ancient DNA studies in the last few years. Thanks to this remarkable new science, we now know that about 70,000 years ago, our planet was remarkably rich in terms of its human variety. It was populated by modern humans, Neanderthals – and the Denisovans who, Reich has recently discovered, must have existed as at least two separate varieties: Siberian Denisovans and the more recently discovered Australo-Denisovans from south-east Asia. In addition, we also know that the Hobbit folk – Homo floresiensis, a race of tiny humans whose remains were discovered in 2003 – were then thriving in Indonesia. In those not too distant days, there were many ways to be a human, it transpires.

“The ingrained notion – that there has only ever been one species of human being, Homo sapiens – is a latterday fiction born of our own self-important view of ourselves. Think instead of the bar scene from Star Wars with all those various people playing and drinking, says the Israeli palaeontologist Yoel Rak. That gives a far better flavour of our evolutionary past. |=|

“In making constant new discoveries about humanity, Reich and his Harvard team are now plunging into uncharted academic waters. “We are going out on a limb on so many different studies,” he says. “It is very lonely and somewhat terrifying. We don’t have the comfort of standing on the shoulders of others. We are the first. That’s why I worry.” |=|

“Reich’s influence in this field has been immense and the output of his department monumental. This year alone he has been involved in producing an analysis that reveals the existence of a previously unknown group of ancient Native Americans from fossil remains uncovered in Alaska; a study that shows the ancient British people who built Stonehenge and other great neolithic monuments were almost completely replaced by invaders from central Asia 5,000 years ago; and a paper that indicates there were at least two waves of settlers, from Taiwan and then Papua New Guinea, which were responsible – 3,000 years ago – for the settling of one of the last pockets of the planet to be reached by humans, Vanuatu.” |=|

Image Sources: Wikimedia Commons

Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Natural History magazine, Archaeology magazine, The New Yorker, Time, BBC, The Guardian, Reuters, AP, AFP and various books and other publications.

Last updated September 2018