Lecture Report
Meave Leakey lectured in San Francisco the evening of Thursday, March 22, the very day of the official publication (in Nature) of her team's claim to have discovered a new genus of hominid. The introducer said that a million people would like to have our seats. Actually, there were a few empty seats at this subscription-only event.
Meave is the wife of Richard, daughter-in-law of Louis and Mary Leakey. Richard and Meave's daughter Louise has now also joined the family business. Meave is a slender, white-haired, cordial woman who gives a good informal talk featuring slides. She began with an historical review of the hominid discoveries, noting the hard-to-classify 1470 skull unfortunately named Australopithecus (or Homo) rudolphensis -- unfortunate because Lake Rudolf has been renamed Lake Turkana and because the skull doesn't really resemble either an Australopithecine or a member of the genus Homo. The general pattern until recently was to fit the fossils into a straight line of descent with minimal side branches. (Of course every discoverer wants his own fossil to be a direct ancestor.) This doesn't make sense because the usual pattern with animal fossils is a bush, with lots of diverse branches rather than a single straight line. The discovery of the latest fossil goes in the bush direction by positing two different genera living at the same time, Australopithecus and now the Kenyanthropus platyops (flat-faced Kenya man), plus the renamed Kenyanthropus rudolphensis. Perhaps in time more variant forms will result in a bush of supposed relatives of the true human ancestor that is yet to be discovered. That is the usual pattern in paleontology. Actual common ancestors are not discovered, but variants abound which allegedly resemble the presumed common ancestor.
Two interesting things emerged in the question period. A man asked if the fossil hunters had a link showing how upright posture evolved. No, Meave Leakey answered, that's a mystery and it seems odd that it happened, as it would have made the creature more vulnerable at the start. Once the hominid learned upright walking then the upper limbs would be freed so human hands could evolve, which in turn would create the conditions leading to evolution of the big brain. But how and why that first step was taken is mysterious.
The last question was double-barreled. First, the woman questioner asked how paleontologists could tell that the specimens were different species or different genera instead of just variant individuals in a diverse population. I was also wondering whether, if the more extreme varieties of modern man were known only as fossils, they would be classified as different species and a marvelous evolutionary tale would be spun around them. Dr. Leakey gave the best answer she could, saying that the skull features where shaped by different ways of living. Of course paleoanthropologists insist that they can tell the difference between varieties of a single species and different species, but there are grounds for skepticism. Modern man aside, how could they know whether there was interbreeding between Australopithecus and Kenyanthropus? One reason that many of us doubt the objectivity of hominid fossil analyses is that there are such powerful incentives to reward those who find a human ancestor, or name a new fossil species (and especially a new genus). It is not just anthropologists who face this temptation; all of us have seen recently how prone many scientists are to hype their discoveries (Mars rocks containing evidence of life, genetic techniques that promise designer babies) to attract fame and funding. The point is not that anyone is dishonest, but that people tend to see what they want to see.
The second part of the woman's question was "Do you ever question the theory of evolution?' Mrs. Leakey refused to answer, which I interpret as a way of saying "No, and I cannot imagine why any rational person would." Take away the assumption that a viable theory of evolution has been proved, and all you have is a collection of variant forms. No wonder persons who have devoted their lives to filling in the details of the presumed human evolutionary sequence are unwilling to doubt the premise that defines their field and gives meaning to their work. The point here is that it is illogical to use the hominid claims as evidence for the theory of evolution. Rather, the claims are based on the assumption that the theory of evolution is true beyond question. If you question the theory, you are doing something the hominid scientists never do.
In Darwin on Trial (pages 83-85, 192-194) I discussed the critique of the hominid claims published in 1970 by the famous British zoologist Sir Solly Zuckerman. On the basis of biometric studies Zuckerman concluded that the Australopithecines then extant were all within the normal range of variation of apes, and that "the anatomical basis for the claim that [they] walked and ran upright like man is so much more flimsy than the evidence which points to the conclusion that their gait was some variant of what one sees in subhuman Primates, that it remains unacceptable." (84) In a 1990 article Zuckerman attributed the success of the Piltdown fraud (only discredited when the fossil became inconvenient) to the fact that the Darwinian anthropologists deluded themselves in thinking that they could "diagnose with the unaided eye what they imagined were hominid characters in bones and teeth." He concluded that "The trouble is that they still do. Once committed to what their or someone else’s eyes have told them, everything else has to accord with the diagnosis."
Meave Leakey is pleasant to listen to, informative and careful to give credit to others, especially including the Africans on her team. She gave an appealing picture of how these fossil finders live and work. Most people in the audience seemed awestruck, and I would classify this as a first-rate presentation of an important doctrine of the naturalistic faith. But I would also say that Zuckerman’s critique is still up to date.
Copyright 2001Phillip E. Johnson. All rights reserved. International
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File Date: 3.27.01