9 Aralık 2007 Pazar

A Farewell to Homo habilis, a Modern Icon

All of us moderns are familiar with the popular from-ape-to-man drawings, which show a series of bipeds starting with an ape and gradually turning into cavemen, and finally into a fine gentleman. You can see these graphs almost everywhere, and advertisers in particular love them. It has become cliché to put a satisfied customer of this or that product at the very end of the evolutionary line. Read the French daily Libération, for example, an ad implies, and become the most sophisticated chap in the from-ape-to-man saga.Of Apes and MenThe gradually evolving “hominids” in these series have names that scientists attributed to them. Usually, the short and hairy ape in the very beginning is Australopithecus, which was not much different from the common chimpanzee in many ways, but which is supposed to have the ability to walk more upright than its relatives. The second hero on the line is Homo habilis, or “handy man,” which is a larger ape, but which, according to some inferences, had the ability to use tools. The third guy is Homo erectus, “the erect man,” which is identical to us modern humans in terms of its body, but only has some unique (and “archaic”) features in its skull. After Homo erectus, generally comes Homo sapiens, in other words, us.These various categories of “human ancestors” look quite convincing and appealing when “reconstructed” and put into a gradual sequence, but when scientific details are examined, it is really not easy to explain how one evolved into the other. One big problem that some paleoanthropologists have noted is the big gap between Homo habilis, which is very much like a big ape, and Homo erectus, which can be considered as a unique, but yet still genuine, human.A 1999 paper published in the academic journal Science by two leaders in the field, Bernard Wood and Mark Collard, actually argued, “Homo habilis should not even be considered a member of Homo, but is rather an australopithecine due to its ape-like skeletal structure.” On the other hand, a 2005 paper in the journal Nature by Robin Dennell and Wil Roebroeks, noted that Homo erectus marks “a radical departure from previous forms… such as Homo habilis.” Homo erectus, these experts said, seems to appear “without an ancestor, without a clear past.”Grandmom and Great-GrandmomNow, the reason why I am telling you all about this is an important discovery made two weeks ago in Kenya by Meave Leakey, the veteran paleontologist. The bones that Mrs. Leakey and her colleagues have found really shakes the standard evolution story, because they prove that Homo habilis and Homo erectus, which are supposed to be two different phases of human evolution, actually coexisted for at least half a million years.“It's the equivalent of finding that your grandmother and great-grandmother were sisters rather than mother-daughter,” said paleontologist Fred Spoor, according to an Associated Press report. The AP news story added that this surprising finding “makes it unlikely that Homo erectus evolved from Homo habilis.” Moreover, it “discredits that iconic illustration of human evolution that begins with a knuckle-dragging ape and ends with a briefcase-carrying man.”In the face of the fall of this “iconic illustration of human evolution,” it would only be fair to recall biologist Jonathan Wells, a critic of Darwinism, and his 2000 book, The Icons of Evolution: Why Much of What We Teach About Evolution Is Wrong. In that much-debated work, Dr. Wells unveiled that most of the standard “evidence” for Darwinian evolution is in fact based on misinterpreted, misrepresented or even faked data. (If you think that Darwinism is demonstrated by the peppered moths of industrial Britain, for example, or that you had fish-like gill slits when you were an embryo, you should read Wells to see how wrong you are.)In his chapter “From Ape to Human: The Ultimate Icon,” Wells also criticized the from-ape-to-man drawings, and revealed that they had very little, if any, factual basis. The recent farewell to Homo habilis, which makes human origins even much more bleak from a Darwinian point of view, vindicates Wells' iconoclasm.Icons Down!Other scientists criticize Darwinism for its failure to explain the origin of the amazingly complex machinery of life. Biochemist Michael Behe's famous book, Darwin's Black Box, for example, tells about the remarkably sophisticated and information-rich structures in the living cell, and shows that the purposeless mechanisms of Darwinian evolution fails to explain their origin. It is like trying to explain the origin of a computer only by referring to the “forces of nature.”But what does that all mean? That there is no evolution? No, I think evolution is a solid fact, established by the fossil record. The nature of 500 million years ago is bewilderingly different from what we have today, and it is pretty clear that there has been an immense change over time. But the idea that this evolution happened only via Darwinian mechanisms – and, especially, in a completely random way – seems to be a philosophical presupposition, not an empirically established fact. There might well be more to the origin of life and man than our modern icons – and their committed preachers – tell us.Writer : Mustafa Akyol

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