Modern Mind

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.’ 22 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 archaeologistHélène 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? 23
    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