Forbidden Archeology_ The Full Unabridged Edition - Michael A. Cremo [470]
Although Leakey was now willing to settle for somewhat primitive Homo habilis as the representative of true humanity in the Early Pleistocene, he had earlier believed that the fully modern human type extended that far back in geological time. As we have seen Leakey initially supported Reck’s anatomically modern skeleton, found in Bed II of Olduvai Gorge (Section 11.1). He also campaigned on behalf of his own finds of sapiens-like human fossils at Kanam and Kanjera (Section 11.2). These finds, all of which Leakey originally thought to be from the Middle and Early Pleistocene, would have been the contemporaries of Australopithecus and Homo erectus. Later, Leakey withdrew his support of a Middle Pleistocene date for Reck’s skeleton when challenged by Boswell, and soon thereafter saw his own finds at Kanam and Kanjera discredited in the eyes of most scientists by the same persistent critic. But in reviewing the controversies over these fossils, we have found, despite some ambiguity, sufficient reason to keep them as evidence for sapiens-like beings in Africa 1–2 million years ago.
In Leakey’s opinion, the major problem with the standard view of human origins was that it resulted in a progression that appeared to violate evolutionary principles. “Australopithecinae or ‘near-men’ show a number of characters which very strongly suggest over-specialization in directions which did not lead towards man,” said Leakey (1960d, p. 184). “The very peculiar flattening of the face, the raising of the eye sockets high above the level of the root of the nose, and the shape of the external orbital angles are among such specializations, as is also the forward position of the root of the cheek-bone process.”
Leakey (1960c, p. 212) also stated: “there are those who still hold that Peking man and Java man should be listed as direct ancestors of Homo sapiens, with Neanderthal and Solo types as intermediate forms, but I cannot support this interpretation, which implies too great a measure of reversal of specialization.” Some of Leakey’s contemporaries assumed the earliest hominids would have features reminiscent of modern apes. According to this view, the path of human evolution, proceeding through the australopithecines and Homo erectus, involves a progressive diminution of these primitive apelike features. According to Leakey (1960d), this idea is incorrect.
Certain features of modern apes, such as large brow ridges, are not primitive, said Leakey, but are instead fairly recent specializations. Proconsul, an Early Miocene African ape thought to be at the very root of the human line, did not have large brow ridges. “There is no trace whatsoever of a ridge of bone over the eyes, separating the brain-case from the face,” wrote Leakey (1960d, p. 175).
Modern humans, with their small brow ridges, according to Leakey, preserve the primitive condition found in the Miocene apes. Australopithecus, Homo erectus, and the Neanderthals, with their large brow ridges, depart, like the modern apes, from this primitive condition. The now-dominant evolutionary progression thus involves an evolutionary reversal that Leakey thought unlikely. Miocene apes with no brow ridges give rise to early hominids with heavy brow ridges, and these hominids in turn give rise to modern humans, with small brow ridges. Furthermore, the Miocene apes like Proconsul have thin skulls, while the australopithecines, Homo erectus, and the Neanderthals have relatively thick skulls. Modern humans have thin skulls, implying another evolutionary reversal.
The advocates of punctuated equilibrium in evolution have a response to Leakey, namely that such reversals can be expected (Stanley 1981, p. 155). One of the great advantages of the punctuated equilibrium theory,