Born in Africa_ The Quest for the Origins of Human Life - Martin Meredith [39]
The following day, Louis Leakey left Nairobi to travel to the United States for yet another gruelling tour of lectures and fund-raising, but on reaching London he suffered a massive coronary and died there on 2 October 1972. Tributes poured in from around the world. One newspaper described him as ‘The man with the million year mind’.
A month later, when Richard Leakey took 1470 to London, he became a media star. The fossil skull made newspaper headlines around the world. It was acclaimed the world’s earliest known man, a million years older than the previous incumbent. A new Leakey era was born.
Within the scientific community, however, 1470 continued to stir controversy. Doubts were raised about the age of the skull. A South African palaeontologist, Basil Cooke, was the first to detect flaws in the dates claimed by Leakey’s team for the KBS tuff. An expert on pig fossils, Cooke had discovered that because of the distinct changes that had occurred during the evolution of their molar teeth, fossil pigs could be used as a palaeontological ‘clock’ to check the work of geologists. From studies he had made at Olduvai and at the Omo River Valley, Cooke had estimated the age of a certain type of fossil pig found there—Mesochoerus—to be about 2 million years. Invited by Leakey to examine Koobi Fora’s fossil pigs, Cooke found that the same type of pig taken from below the KBS tuff had been dated by Leakey’s team as at least 2.6 million years. The Koobi Fora site and the Omo site were less than 100 miles apart. There seemed to be no logical reason for such a discrepancy in the evolutionary development of the same species. The possibility emerged therefore that Leakey’s dates were at fault and that the 1470 skull and Koobi Fora tools which he had claimed to be the world’s oldest were no older than the oldest hominids and tools from Olduvai—2 million years.
The initial dating of the KBS tuff had been carried out in England by two British experts, Jack Miller, a geophysicist at Cambridge University and Frank Fitch, a London-based geologist, using a new variant of the potassium-argon method that had astonished the scientific world with its revelation of Dear Boy’s age. When queried about the validity of their date, they stuck fast to 2.6 million years. With a vested interest in the older date, Leakey too entrenched himself. But the evidence against him began to mount. Not only did the pig data between Omo and Turkana not correlate; neither did various other animal data, including that for elephants, horses and antelopes. Matters were made worse when it became evident that some of the fieldwork undertaken by Leakey in the early years had been seriously flawed.
The KBS tuff controversy, as it was called, soon developed into a full-blown feud between two rival groups: Leakey’s team in Kenya, adamant that the tuff was 2.6 million years old, and Clark Howell’s American team in charge of the Omo River Valley sites, insisting that it was no older than 2 million years old. Both sides resorted to personal attacks. Howell’s team possessed far more expertise and was scornful of Leakey’s ‘amateur’ status and defective fieldwork. But it was Leakey’s team that had made the most spectacular gains and achieved worldwide fame. A Rift Valley conference in London in 1975 was marred by scientists shouting at each other.
The turning point came when an independent test on new KBS tuff samples was carried out by Garniss Curtis at his potassium/argon laboratory at Berkeley, California. The oldest date he produced was 1.8 million years. Subsequent tests on the Koobi Fora pig fossils also confirmed they were no older than 2 million years, the same age as their counterparts at Omo and Olduvai.
Thus, the 1470 skull was assigned to an age contemporaneous with Homo habilis: about 2 million years old. Indeed, most scientists eventually concluded that it belonged to the same species, helping Homo habilis to gain recognition as a real biological entity.
Meanwhile, another challenger