From the July 1987 issue of the Socialist Standard
Recently I attended a lecture at the Darwin Theatre University College London - "Two Feet Rather Than Four: The Distinctive Human Adaptation"; speaker Lesley A. Aiello, Lecturer in Anthropology. The précis of the title was: "Bipedal locomotion and the accompanying specialisation of the human hand for tool use and manipulation are distinctive human characteristics. The evolution of these features, as revealed in the fossil record, is traced over the past 4 million years of human prehistory".
This suggested that the lecturer regarded bipedal locomotion as the most important feature of all human biological characteristics. During the course of the lecture it became obvious that the lecturer was very knowledgeable about the limited field with which she was dealing but the lecture was given in so hurried a way that I formed the impression that she was performing an obligation rather than engaging in a genuine desire to impart knowledge. It confirmed what I already thought to be the case - that very few anthropologists understand the overall significance of their field.
I have no doubt that most students of anthropology and related disciplines are aware of the controversy over the years in relation to the evolutionary origins of homo sapiens. For example, did the enlargement and complexity of the brain in hominid evolution take place before or after upright stance and bipedal locomotion had been achieved? Was upright stance a necessity for the evolution of vocal tract anatomy? Were the Neanderthals members of sapiens or were they a different species? If so did sapiens evolve directly from them? These questions and many more have been debated at great length.
However, it seems to me that what we, and in particular the anthropologists, should also find important is: when homo reached the sapiens stage in evolution, what then happened was that an animal made its appearance on the evolutionary scene equipped with a unique combination of biological attributes making it the most superior organism that had ever existed. And it was not any one of these attributes which gave it superiority. It was not just upright stance with bipedal locomotion, or prehensile hands with opposable thumbs, stereoscopic binocular vision, audio and vocal tract anatomy, or the relatively largest and most complex brain of any organism alive or long since extinct, but a reciprocal and complimentary combination of them all. working one with the other.
We might say it was the supreme achievement of biological evolution by natural selection and it brought with it a new dimension to the evolutionary process — cultural evolution which has rendered further biological evolution by natural selection comparatively unimportant. When someone says to me: what do you think of human nature? What immediately springs to mind is precisely that unique combination of biological attributes possessed by our species, the sum total of which is human nature (as distinct from human behaviour) and is not necessarily connected with human behaviour except that it genetically lays the foundation for human behaviour of virtually unlimited variation and adaptability.
Theodosius Dobzhansky in 1956 described this process admirably when he wrote:
Evolution is a response of living matter to the challenges of environmental opportunity through the process of natural selection. The response of the human species, or rather of the species ancestral to man. was a unique one; it developed the genetic basis for the accumulation of, and for the extragenic transmission of a body of learned tradition called culture. The relations between culture and its genetic basis are all too often misunderstood. This topic is too complex and important to be dealt with lightly, but the basic facts are simple enough. Genes determine the possibility of human speech but not what is spoken. The cultural evolution of mankind is superimposed on its biological evolution; the causes of the former are non-biological without being contrary to biology, just as biological phenomena differ from those of inanimate nature but are not isolated from them. (Evolution At Work — one of a collection of essays in Ideas on Human Evolution. Ed. William Howells).
I think that it is true that most natural scientists working in the field of anthropology would agree that the Cro Magnon type of homo sapiens of about 40,000 years ago. was not very different anatomically and physiologically from present-day humans and from 40,000 years ago up to the present there has not been any significant biological modifications to our species; and I suggest for the very good reason that there been no necessity for such changes, the biological equipment that humanity already has is sufficient to ensure adaptability to any environment.
Furthermore, there has been no speciation; variation there most certainly is but there is no evidence that any groups of human beings, even those in the most geographically remote parts of the world, have evolved any mechanism which makes them reproductively isolated from any other groups. There has been no necessity for that to happen, because of the ability of the human species to adapt and to change its environment and in so doing to determine its own destiny. Natural selection alone as far as homo sapiens is concerned is no longer operative for further evolution. It can only work to preserve and augment the human ability to create, absorb and transmit culture.
This does not mean, however, that we are making a very good job of it. It is with human behaviour that we have a problem. The human species is at present rushing towards extinction in relation to geological time. (I think that rushing is the appropriate term to use) and if it does not change its behaviour by introducing the much more rational and harmonious social system of socialism (which it is quite capable of doing) it could become extinct very quickly. That would be an irony indeed, when we consider that the dinosaurs, animals which tended towards having very limited brain power, nevertheless managed to exist for about 125 million years and yet the supreme achievement of biological evolution would have become extinct after only about one 3000th part of that time.