Becoming Human. Evolution and Human Uniqueness by Ian Tattersall, OUP, 2001.
Like all the other life-forms on this planet, we humans are the product of a process of evolution from earlier life-forms. Our immediate ancestors will have been ape-like animals which had evolved to walk upright. The fossil record suggests that there will have been many species of such animals, from one line of which we are descended. All the other lines not only became extinct but left no descendants either. The last of these other types of Homo to go extinct were the Neanderthals, a mere (in evolutionary time) 27,000 years ago.
All this is described by Tattersall, who is the curator of the Department of Anthropology at the American Museum of Natural History in New York, in this paperback edition of a book that was first published in 1998. According to him, although there was no predetermined course of evolution leading to us as the “highest form” of life, there is a feature that distinguishes us from all other life-forms—the capacity for symbolic thought, i.e. the ability to generate and manipulate complex abstract symbols (words naming parts of our environment and relationships between them). This allows us not just to react to the external world but to refashion it. This of course is tied up with language and it is what makes us unique. It has enabled us to develop technologies that have changed both the rest of nature and the societies in which we live.
Tattersall speaks of “human capacity” (as opposed to “human nature”) and clashes with those, such as the sociobiologists and the evolutionary psychologists, who have a very narrow view of this capacity, seeing it as being severely limited by our genes. But, Tattersall points out, while our genes can’t be ignored “they only intervene in our behaviours in an indirect way, by programming the development of our brains”. Therefore, “if we are to understand the complexities of our behaviour, it is to our brains, not directly to our genes, that we have to look”.
When we do this then, we can add, we find that our brains allow us, as a species, to adopt – and, as prehistory and history bear out, we have in fact adopted – a great variety of different behaviours depending on the natural, economic and social environments we have found ourselves in. So, contrary to the biological determinists of various hues, “human nature” is not a barrier to socialism. On the contrary, our biologically evolved and inherited “human capacity” will allow us to live in a socialist society.
Tattersall has his own particular theory of how our brains developed, which is not accepted by all anthropologists and palaeontologists. He suggests that the ability to think abstractly, and to express such thoughts vocally, arose for other reasons than directly to be able to do these, for instance perhaps as a result of the mental images involved in fashioning tools, in one line of Homo which only later exploited this capacity. Hence his view that the Neanderthals did not use symbolic language.
This is a neat refutation of the views of those who claim that our brains only evolved for life on the open grasslands of East Africa and that therefore we have “stone age minds” which make it difficult for us to live under capitalism let alone in a socialist society. In any event, Tattersall points out, the idea that the brains of us modern humans (Homo sapiens) evolved out of living in a single environment has been overstated. During the time that the various different species of Homo evolved, and all except the line that led to us became extinct, the natural environment was unstable. The Earth cooled and warmed and cooled again, shifting patterns of vegetation even in East Africa. “It is out of this ecologically and geographically unstable world that our ancestors ultimately arose,” concludes Tattersall. “The widely cited notion of a monolithic ‘ancestral environment’ that, through our genetic heritage, still conditions our behavior today is simply untenable”.
Adam Buick
No comments:
Post a Comment