Modern Mind: An Intellectual History of the 20th Century (121 page)

Fossey found that different gorillas had very different characters, and that they used some seven different sounds – including alarm calls, pig-grunts when travelling, rebuttals to other sounds, and disciplinary enforcements between adults and young. Unfortunately, Dian Fossey was unable to further her studies;
at the end of 1985 she too, like the Adamsons, was murdered. Her black tracker and her white research assistant were both accused, though the charges against her tracker were dropped. Fearful of not receiving a fair trial, the white assistant fled the country, later to be convicted in his absence.
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In the short run, Fossey’s battle against poaching was more important than her ethological observations, as her death shows. But only in the short run. For example, her sensitive description of the gorilla Icarus’s response to the death of another, Marchesa, raised profound questions about gorilla ‘grief and the nonhuman understanding of death. In many ways, the evolutionary psychology of gorillas is even more enlightening than that of chimpanzees.

George Schaller, director of the Wildlife Conservation Division of the New York Zoological Society, made it his life’s work to study some of the ecologically threatened large animals of the world, in the hope that this would contribute to their survival. In a long career, he spent time studying pandas, tigers, deer, and gorillas but his most celebrated study, published in 1972, was
The Serengeti Lion.
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This book, which also included sections on the cheetah, leopard, wild dogs, and hyenas, took up where the Adamsons left off, in that Schaller was much more systematic and scientific in his approach – he counted the number of lions, the times of the day they hunted, the number of times they copulated, and the number of trees they marked out as their territory.
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While this did not make his book an enthralling read, his overall picture of the delicate balance in Africa between predator and prey had a marked effect on the ecological movement. He showed that far from harming other wildlife (as was then thought), predators were actually good influences, weeding out the weaker vessels among their prey, keeping the herds healthy and alert. He also made the point that although lions were not as close to man as chimpanzees or gorillas were in phylogenetic terms, they were quite close in ecological terms to, say,
Australopithecus.
He argued that lions’ hunting techniques were far more likely to resemble early man’s, and his own studies, he said, showed that lions could hunt efficiently in prides without any sophisticated vocalisation or language. He did not therefore think that language in man necessarily evolved to cope with hunting, as other scholars believed.
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The final study in this great scientific safari on the Kenya/Tanzania/Uganda border was Ian Douglas-Hamilton’s investigation of elephants. A student of Nikolaas Tinbergen at Oxford, Douglas-Hamilton had originally wanted to study lions but was told that George Schaller had got there first. Douglas-Hamilton’s study, published as
Among the Elephants
in 1975, was a cross between the Adamson-Goodall-Fossey approach and Schaller’s more distanced research, mainly because elephants are far harder to habituate to in the wild.
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He observed that elephants keep to family and kinship units and appear to show affection to other family members, which extends to a characteristic trunk-to-mouth gesture. Although he would never have been so anthropomorphic as to say this was ‘kissing,’ it is hard to know how else to describe it. Several family units make up kinship units. At times of abundant food supply, after the rains, elephants come together in massive 200-strong herds, whereas in drought they break up into smaller family groupings. Elephants show an extraordinary
amount of interest in dead elephants – offspring will remain alongside the body of a dead mother for days, and a herd will sometimes dismember the carcass of an erstwhile colleague. Douglas-Hamilton’s research meticulously catalogued which elephant stood next to which, and showed that there were clearly long-term ‘friendships.’
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As with the other big mammals of Africa, Douglas-Hamilton observed great individuality among elephants.

Much farther north than Olduvai, but still part of the Rift, the great valley splits into two: one part of the Y extends northeast into the Gulf of Aden, whereas the other heads northwest along the Red Sea. The area between the two arms of the Y is known as the Afar Triangle and is part of Ethiopia.

To begin with, the sites in Afar had been excavated by the Leakeys, especially Louis’s son, Richard. They had dug there by invitation of Emperor Haile Selassie, who was himself interested in the origins of humankind and, on a state visit to Kenya in 1966, had met Louis Leakey and encouraged him to come north. Early digs consolidated the picture emerging farther south but were overshallowed by a discovery made by a rival French-American team. The guiding spirit of this team was Maurice Taieb, a geologist, who made the Afar Triangle his speciality (it was geologically unique). He called in a palaeontologist he had met elsewhere in Ethiopia, Don Johanson, a graduate student at Chicago University. Taieb had found an area, named Hadar, which he regarded as very fruitful – it was several thousand square kilometres in size and very rich in fossils. An expedition society was formed, which initially had the Leakeys as members. What happened on that expedition, and subsequently, became one of the most controversial incidents in palaeontology.

In November 1974, four miles from his camp, Johanson spotted a fragment of an arm bone sticking out of a slope. At first he thought it belonged to a monkey, but ‘it lacked the monkey’s distinguishing bony flange.’
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His eye fell on another bony fragment higher up the slope – then a lower jaw, ribs, some vertebrae. He had in fact found the most complete hominid skeleton yet discovered, about 40 percent of the entire structure, and from the shape of the pelvic bone, almost certainly female. That night, back at camp, the team celebrated with beer and roast goat, and Johanson played the Beatles song ‘Lucy in the Sky with Diamonds’ over and over again. Famously, and unscientifically, the skeleton, officially recorded as AL 288–1, became known as ‘Lucy.’
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The unparalleled importance of Lucy at the time was the fact that her anatomy indicated she had walked upright and could be precisely dated as being between 3.1 and 3.2 million years old. Her skull was not complete, but there was enough of it for Johanson to say that it was in the ape-size range. Her molar teeth were human-like, but the front molars were not bicuspids like ours.

Haile Selassie was overthrown in September 1974 in a coup which resulted in a Marxist military dictatorship in Ethiopia. This made work difficult, but Johanson managed to return and in 1975 made a yet further extraordinary discovery: a ‘first family’ of thirteen individuals – males, females, adults, juveniles, children, some two hundred fossils at one site, Site 333, as it became known. And in the following year, 1976, together with the French archaeologist
Hélène Roche, he found simple basalt tools, dating back to 2.5 million years. This all meant a complete revision of humankind’s origins. Tool-making was much older than anyone imagined, as was upright walking. And it was clearly something indulged in first by
Australopithecus,
not the
Homo
genus.

Further finds in Hadar were prevented by another deterioration in the political situation in Ethiopia (another military coup in Addis Ababa). During this interregnum the southern end of the Rift Valley came back into the spotlight. In the mid-1970s Mary Leakey had been working in Laetoli, a site thirty miles from Olduvai, an area of sandstone gullies that cut into a plateau, very different from the gorge. She had been going there for many years and had recently found two jaws dating from 3.6 to 3.8 million years ago. In the last week of July 1976 she was joined by four other scientists, among them Andrew Hill and Kay Behrensmeyer. The newcomers, in high spirits, were all taken on a tour of the site on the morning after their arrival, and an elephant-dung fight broke out. Ducking into a flat gully to look for ammunition, Hill and Behrensmeyer came across a hard layer of volcanic ash – in which, as they suddenly noticed, there were elephant footprints. They dropped to their knees for a closer look, and then called the others. These were not fresh prints, but fossilised, and scattered near the elephant tracks were those of buffalos, giraffes, and birds. There were even a few ancient raindrops. What must have happened was that a spurt of volcanic ash, given off by a nearby mountain, had settled and then been rained upon, turning it into a form of cement. While this ‘cement’ was wet, animals walked across it, then another layer of ash was deposited on the top. Over the centuries, the top layer had weathered away to reveal the fossil footprints. It was an unusual find, but Mary Leakey told everyone to look out for hominid footprints – that would certainly make news. They searched all through August, but not until one day in September did they find some prints that looked hominid, with signs of a big toe. There were two sets, one much larger than the other, and they stretched for eighteen feet across the ancient ‘cement.’ In February 1978 Mary Leakey felt confident enough to announce the discovery. What was especially interesting was that the volcanic ash was dated to 3.7 million years ago, slightly earlier than the Ethiopian sites. From the pattern of indentations, some experts thought that whoever this hominid was, he did not walk upright all the time. So was this the period when man first
began
to walk upright?
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The answer did not come from Mary Leakey. The Laetoli bones and jaws had been given to Tim White, an American palaeontologist, whose job it was to describe them meticulously. However, White, a difficult man, fell out with both Richard and Mary Leakey. Worse, from the Leakey point of view, he subsequently teamed up with Don Johanson, and this pair proceeded to examine and analyse all the fossils from Laetoli and Hadar, all those aged between 3 and 4 million years old. They revealed their conclusions in 1979 in
Science,
claiming that what they had was a single species of hominid that was different to, and the ancestor of, many others.
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This species, which they named
Australopithecus afarensis,
they said was fully bipedal and showed marked sexual dimorphism (the males were much bigger than the females), though even the males were
no more than four feet six. Their brains were in the chimpanzee range and their faces pronounced, like the apes; their teeth were halfway between those of the apes and humans. Most controversially, Johanson and White claimed that
A. afarensis
was the ancestor of both the
Australopithecus
and the
Homo
genus, ‘which therefore must have diverged some time after three million years ago.’
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At the beginning it had been Johanson and White’s intention to include Mary Leakey as a coauthor, but Mary was unhappy with the label
Australopithecus
being attached to the fossils she had discovered. The convention in science is for the discoverer to have the first ‘say’ in publishing the fossils that he or she finds, and to name them. After that, of course, other scientists are free to agree or disagree. By including Mary’s discoveries in their paper, Johanson and White were not only breaking with tradition; they knew by then that they were specifically going against her own interpretation. But they were anxious to claim for
A. afarensis
the tide of common ancestor of almost all known hominid fossils and so went ahead anyway. This caused a bitter feud that has never healed.
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Beyond the personal dimension, however,
A. afarensis
has provoked much rethinking.
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At the time it was given its name, the predominant view was that bipedalism and tool using were related: early man walked on two feet so as to free his hands for tools. But according to Johanson and White, early man was bipedal at least half a million years before tool using came in. The latest thinking puts bipedalism alongside a period of drying in Africa, when the forest retreated and open savannah grasslands spread. In such an environment, upright walking would have offered certain selective advantages – upright early man would have been faster, his body would have cooled more quickly, and he could have roamed over greater distances, with his hands free to carry food home, or back to his offspring. So although the bitterness was personally unpleasant, it did provoke useful new ideas about man’s origins.
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Since the discovery of the helical structure of DNA in 1953, the next theoretical advance had come in 1961, when Francis Crick and
Sidney Brenner
in Cambridge had shown that the amino acids that make up the proteins of life are actually coded by a triplet of base pairs on DNA strands. That is, of the four bases – (a)denine, (c)ytosine, (g)uanine, and (t)hymine – three, in certain arrangements, such as CGT or ATG, code for specific acids. But more practical advances involved two ways of manipulating DNA that proved integral to the process of what became known as genetic engineering. The first was cloning, the second, gene sequencing.

In November 1972
Stanley Cohen
heard a lecture in Hawaii delivered by
Herbert Boyer,
a microbiologist from the University of California at San Francisco. Boyer’s lecture was about certain substances known as
‘restriction enzymes.’
These were substances which, when they came across a certain pattern of DNA bases, cut them in two. For example, every time they came across a T(hymine) followed by an A(denine), one restriction enzyme (of which there are several) would sever the DNA at that point. However, as Boyer told the meeting, restriction enzymes did more than this. When they cut, they did
not form a blunt end, with both strands of the double helix stopping at the same point; instead they formed jagged or steplike ends, one part jutting out, slightly longer than the other. Because of this, the ends were what scientists labelled ‘sticky,’ in that the flaps attracted complementary bases.
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At the time he attended Boyer’s lecture, Cohen was himself working on plasmids, microscopic loops of DNA that lurk outside a bacterium’s chromosome and reproduce independently. As Cohen took in what Boyer was saying, he saw an immediate – and revolutionary – link to his own work. Because plasmids were loops, if they were cut with one of Boyer’s restriction enzymes, they would become like broken rings, the two broken ends being mirror images of each other. Therefore, strips of DNA from other animals, and it didn’t matter which (a lion, say, or an insect), if inserted into the bacterium with ‘split rings,’ would be taken up. The significance of Cohen’s idea lay in the fact that the plasmid replicated itself many times in each cell, and the bacterium divided
every twenty minutes.
With this form of replication and division, more than a million copies of the spliced DNA could be created
within a day.
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