An Emotional Subject
- The Myths of Human Evolution by Niles Eldredge and Ian Tattersall
Columbia, 197 pp, $22.50, November 1981, ISBN 0 231 05144 1
A great many new facts about human evolution have been found in recent years, all of them strengthening the belief that our ancestors were rather like apes. Indeed it becomes more and more likely that there were no fully human creatures on earth until as recently as forty thousand years ago. It is a great pity that these new discoveries have been written up in a sensational manner by some anthropologists. The title of this book, The Myths of Human Evolution, panders to the idea that there is some doubt about whether evolution has occurred at all, which is of course just what creationists are saying so vociferously in the United States. Their clamour, and the political and educational issues raised, make the subject into News, and one can’t help suspecting that the authors of the book (or their publishers) mean to exploit this interest with their title.
In fact both authors are reputable scientists who have no doubts that evolution has occurred. The question they are raising is whether it goes on ‘gradually’ or by ‘sudden jumps’, with long periods in which species remain unchanged. The ‘myth’ they wish to attack is that evolution proceeds by slow adaptive change. This was of course what Darwin himself proposed and is probably still the view of most biologists today. The authors call it a ‘myth’ because its truth is ‘taken for granted’. They believe that it grew up because ‘Darwin got his notions of how evolution works from general ideas of change around him, and he characterised evolution in these terms as a technique to convince his peers that species are not the indelible fixed sort of entities biologists had long considered them to be.’ I wonder whether this is really a correct account of how Darwin worked. Other ‘myths’ are also attacked in the early part of the book. ‘Reductionism’, which is ‘explaining all human behaviour in terms of biological principles (themselves reduced to genetics)’, seems to be one of the culprits, and is due to ‘physics envy’, generated by the American public’s belief that the physicist is the paragon of what a scientist ought to be. How this affects evolution theory is not clear, and it is apparently the fault of sociobiologists who are ‘reductionists’.
Another ‘myth’ is that evolution has been ‘progressive’. This idea may have been inherited, as the authors suggest, from the Victorian concept of social evolution: but surely it is now possible to agree that in the 3000 million years of evolution from the earliest known bacteria to mammals and flowering plants there has been a change that can be called an advance. The higher animals and plants are more complex systems than their ancestors. They have devices that enable life to continue in conditions far different from the sea in which it first arose. In this sense ‘progress’ is not a myth: it has occurred. But many organisms remain simple still – the problem is to find out why some have changed and some have not.