Steve Jones - The Language of the Genes

The patterns of genetic change which build up through mutation can be used to make an international pedigree. Africans form a distinct and ancient branch of the lineage. American Indians group together with their Asiatic ancestors, and Australia and New Guinea are a separate offshoot. A family tree of languages can be made in the same way. English, German and Bengali cluster together into the Indo-European family, and Chinese and Japanese into a different group. A language tree based on a few words — one, two and three; head, ear and eye; nose, mouth and tooth and so on — looks much like one made with a more complete vocabulary. Such limited word lists are used to classify less well known tongues (such as those of Africa or the New World) with some success.

One controversial claim has it that all the languages of the world can be classified into just seventeen distinct families, with the thousand or so native languages of the Americas failing into only three; Eskimo-Aleut in the far north, Na-Dene in southern Alaska and Canada, and all the others south to Patagonia as a single group, Amerindian. The wide distribution of this family contrasts with the pattern in Papua New Guinea, where a much smaller space contains eight hundred languages, many almost unrelated to each other. The genetics and the speech of the Americas and of Papua New Guinea shows parallel patterns: Americans are rather uniform in their DNA and in their language, while the Papuans vary from valley to valley. The highest concentration of language diversity lies in the Caucasus, between the Black and Caspian Seas. In an area twice that of Britain forty languages are spoken, some in just a single village. Unfortunately we know little of the genetics of that fractious part of the world.

A tree of the relationships of all the world's languages makes it possible to guess — wildly — at some of the original words at the base of them all. Russian linguists have attempted to reinvent Nostratic, the twelve-thous.uid-year-old tongue thought to be the ancestor of Indo-European and its relatives. These include the Elemo-Dravidian tongues of parts of India, the Altaic languages which include Turkic and Mongolian and an Afro-Asiatic group spoken in the northern half of Africa. They have reconstructed over a thousand 'root' words. Tik, for digit, finger or toe, is one of these, kujna for dog another. No shared words refer to agriculture, so that this proto-language may indeed derive from before the farmers.

The world language tree looks somewhat similar to the genetic tree. Both come to the same root in Africa and both show a split between Australasia and other Asian peoples. Not too much should be made of this, as words can spread by learning, which genes cannot. As a result, the pedigree of words looks more like a network than a branching river (to eat an avocado while paddling a kayak unites three distant families in a single sentence). In addition, trees of genes need not always reflect that of the population from which they come {particularly if certain genes spread through whole groups because — as for malaria resistance — they are advantageous). Even so, the general similarity between the two means of communication suggests that perhaps language itself dates back to the origin of humankind.

Speech marks a huge jump in the speed of information transfer. To spell out this sentence, letter by letter, would take ten times longer to transmit the information than it would to speak it. The plight of the deaf and dumb shows how inui It <>l life depends on an ability to speak. Dyslexia

A difficulty in recognising written words, often among people otherwise of high intelligence — has been tracked down in part to specific genes on two human chromosomes; and these may be candidates for that select group that may differentiate ourselves from our primafe relatives. It is hard to imagine a society which could work without language. Early modern humans underwent changes in skull shape and in the position of the larynx that may have marked the first ability to articulate a sound. Such physical changes suggest that speech may have made us human in the first place.

Shelley felt as much: in Prometheus Unbound he has his hero 'give men speech, and speech created thought'. Not everyone agrees. Some suggest that even Neanderthals had a sophisticated language which disappeared when they themselves became extinct. There is a hint of an earlier linguistic dawn. Apes in groups spend much of their time grooming, to show their fellows that they belong. If the first humans reassured their companions as apes do, they might, because of the size of each band, have had to spend half their time grooming. Speech, even when primitive, is a better way of calming one's fellows than is touch. The first sentences may have been words of comfort.

Nobody will ever be able to speak Neanderthalish, if it existed. The sixteenth-century German philosopher Becanus was convinced that the language of Eden was Old German, and that the Old Testament had been translated from this into Hebrew (the Emperor Charles V, in contrast, spoke French to men, Italian to women, Spanish to God and German to horses). Soon, there may be a chance to find out the truth. The fossils and the genes have already given us clues about where and when Ad;nn met Eve; before long, we may be able to guess at what they said to their errant children.

American bird-watchers know that the common sparrow — the bird that hops around in English gardens — has a bigger body and shorter legs in the north than in the south of the United States. The same is true for sparrows in northern and southern Europe. Creationists see in this a divine arrangement to ensure so that each species fits into the economy of nature; cold places, wherever they are, meriting a subtle change in God's plan.

If the deity does have a plan, it seems to work in the same way for humans. People from the far north have shorter arms and legs and more compact bodies than do those from the tropics. Olympic long-distance records tumbled after East Africans with their long legs began to take part. Before Darwin the ability of Africans to cope with heat and Eskimos with cold was excellent evidence for divine action. The Creator had seen to it that each people suited their homeland, as proof of what a wonderful designer he was. As the nineteenth century cleric William Paley argued, if one found a watch, beautifully designed as it was, then one must accept the existence of a watchmaker. The perfection of humanity proved in the same way that there was a God. This idea seemed so powerful that it was carried to absurd lengths. Voltaire, in Candida, parodied it with Dr.Pangloss and his delight at the perfection with which noses had been designed to carry spectacles. Freud, a keen Darwinist, commented that one might just as well argue that the fact that cats have two holes in their skin where their eyes are could be explained in the same way.

The argument from design, as it is called, has a problem, for sparrows at least. In fact, English sparrows have not been in the Americas since the time of creation. They arrived little more than a hundred years ago. A few were brought from England and released in Brooklyn in the 1850s. Within about a century, a hundred sparrow generations, they spread to fill the continent. How did they come to resemble so closely the birds of their native land?

The answer lies in natural selection: in inherited differences in survival and reproduction. Studies of marked sparrows in Kansas show that large individuals with short legs survive better in icy weather. They hence have a greater chance to breed and to pass on their genes when spring comes. Those released a century ago brought from their native land genes for large or small size and stocky or graceful legs. In the north, the big squat birds did better, but in those that spread to the torrid south the opposite was true. In a few generations, American sparrows evolved just the same geographic patterns as those found on the other side of the Atlantic. Natural selection had done its work.