The Language of the Genes

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The Language of the Genes Page 23

by Steve Jones


  In the same way, the population of Orkney, whose native language is a Scandinavian one, is distinct from the rest of Scotland. Hven dialects may mark biological barriers. France has a small genetic step between those who speak the langue d'oc (southern French) and speakers of the northern langue d'o'tl. Genes and language tell the same story.

  Their concordance is not always absolute. The Balkans have had, and retain, a tumultuous history of movement and conquest which has obscured any relationship hetween linguistic and genetic units. Hungarians, too, speak a distinct language, but remain biologically close to their neighbours. The Magyar conquerors from the east imposed a language on their subjects, but were too few in number to make much impact on the genes. In some places genetic steps exist even within groups who speak the same language. The east of Iceland is somewhat distinct in its genes from the west, although both speak Icelandic. This may be a relic of the history of settlement of western Iceland by Scandinavian immigrants who brought wives and servants from Ireland.

  The language of the Basques, like their genes, seems to be unrelated to any other. The Latin author Mela wrote of his bafflement at the names of peoples and rivers which meant nothing in any tongue known to him. Francis Galton himself, who often went on holiday to the Basque country, recalled 'the legend that Satan himself came here for a visit. Finding after six years that he could neither learn the language nor make the Basques understand his, he left the country in despair.1 Satan's problem is illustrated by a typically impenetrable Basque proverb: 'Oinak zewrbitz-atzen du eskua, eta eskuak oina" ('the foot serves the hand and the hand serves the foot'). Basque may be the last remnant of the speech of Europe before agriculture. Its sole apparent relative is spoken by some of the isolated peoples of what was once Soviet Georgia. Many Georgians believe that their own language was taken to the Basque country by Tubal, grandson of Noah, and moves were onu1 nloot to find a basque to succeed to the throne of Georgia.

  Safe in their mountains the Basques resisted invaders, so that their ancient tongue, a language of hunter-gatherers, lives on among its half-million speakers. The skeleton of Cro-Magnon himself was found in a part of France which, its place-names suggest, was once in the Basque country. There might even be a linguistic, and perhaps a genetic, link between Cro-Magnon, one of the first Europeans, and the Basques. This last remnant of a lost European economy is under threat. Today, Basque genes stretch for much further than the language: east to Zara-goza, now a Spanish city, and north into France. Their economy was destroyed long ago. Now their speech and their culture may at last be squeezed out by modern society. Like the Etruscans — who also spoke a non-Indo-European language — only their genes will be left

  DNA can say much more about ancestry than can language. The forefathers of today's Britons come from Europe, Africa, India and even China, but they speak English. Books and pictures will in time blur the links between genes and language, but we are still in a phase of history where enough remains of the linguistic past to speculate about the origins of speech and perhaps of modern man himself.

  Where did Indo-European languages come from? The first recognisable member of the group was Hittite, written in cuneiform and spoken in Turkey four thousand years ago. Modern Indo-European tongues can sound quite different. 'Our father, who art in heaven' is 'Ein Tad, yr hwn wyt yn y nefoedd"1 in Welsh, 'Patera mas, pou eisai stous ouranous1 in Greek, 'Otcbe nasb, suscij na in Russian and 'He hamarc svarghast pita' in Hindi.

  Nevertheless, some words for widely used objects are held in common. They can be used to guess where the languages originated. Indo-European tongues share several terms for domestic animals and crops. The ancient word for sheep, owis, has been inferred from the Latin ovis, Sanskrit avis and English ewe. Cow was kou, and water yotor. There are similar words for corn, yoke, horse, and wheel, too.

  Perhaps the Indo-Europeans were farmers, who brought their language with them as they spread. Quite where their homeland may have been is uncertain. Their language began long before the first record was preserved. They might represent a wave of invasion of Kurgan people from the Pontic steppes, north and east of the Black Sea. This was the land of the Sredny Stog horsemen. Their journeys began about 4500 BC, long after the origin of agriculture. Some believe that the Indo-Europeans invaded much earlier and brought farming with them as they migrated from Asia Minor three thousand years before the Kurgans. Some of the Indo-European peoples — and languages — who built Europe may have begun to diverge before they moved from their homes in the east. It may be hard to trace just who, if anyone, among today's nations and tongues are the ancestors of modern Europeans.

  Language, archaeology and genes all bear witness to an invasion of Europe from the east. Farming, genes and speech are intimately related. In some place, farmers moved into an empty — or scarcely populated — land rather than into a successful hunting economy (as it did in Europe). Rice growers of the Far East around the Yangtse basin took their language as well as their DNA with them as they filled the Pacific. At one time these Austronesian languages were the most widespread of all, with a territory that extended from Madagascar to Hawaii and Easter Island. In Africa, farmers moved south, to fill western and southern parts with Bantu speakers.

  Today's technical advances, from the book co the internet, provide new ways of speaking to people. They have led to the erosion of the nation-states that have so long shaped history. We can now reach anyone in the world as soon as they can get to a telephone. New work on global patterns of language suggests that the first social breakthrough of all also involved a new form of communication technology.

  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 bot
h 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.

  Chapter Twelve DARWIN'S STRATEGIST

  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.

  Natural selection was Darwin's Big Idea. It gave him a mechanism that drove evolution without the need for a designer to supervise every step. The Origin of Species starts with life on the farm. It shows how domestic animals emerged from wild ancestors because of preferences, often inadvertent, for one type over another. Selective breeding, the choice of the best to produce the next generation, soon caused new forms to appear.

  If farmers could do so much in a short time, then nature could do more. 'What limit can be put to this power, acting during long ages and rigidly scrutinising the whole constitution, structure and habits of each creature favouring the good and rejecting the bad? I can see no limit to this power, in slowly and beautifully adapting each form li> the complex relations of life.'

  The engine — il not the engineer-of evolutionary change is the preservation of favoured types in the struggle for life. Change is inevitable in any system, be it genes or language, which makes errors of transmission from one generation to the next. This may be evolution, but it is change at random. It cannot lead to the passage from simple to complicated which made humans from their modest predecessors. Natural selection takes advantage of the fact that, each generation, inheritance makes mistakes. Because some improve the ability of their carriers to cope with what nature throws them they copy themselves more successfully. Darwin's mechanism sorts out the best from what accident supplies. It gives a direction to evolution and allows life to escape from the inevitability of extinction. This ts as true for humans as for any other creature.

  Selection is a simple idea. The notion is used by computer experts. They programme their toy not with the precise details of what is needed, but with a guess of what might work; and allow this to make rough copies of itself. By choosing the most successful, they make rapid progress and can, in a few generations, evolve computer birds that flock like starlings, mathematical ants able to follow trails and programmed flowers as beautiful and unexpected as any product of nature. Literature, too, is not immune to artificial natural selection. Just a few unpretentious themes underlie simple works like mediaeval folk tales or children's stories. To feed them into a computer with a small change to each motif and to choose the best leads to the emergence of brand new and coherent versions.

  Humans are not safe from the Darwinian machinery. For most of history, most people died before they were old enough to pass on their genes. Even among the survivors, some had more children and some fewer. If any of these differences arc influenced by inheritance, then Darwin's mechanism is at work and the next generation will differ from its parents. Selection will, in time, lead to change.

  The power of the evolutionary machine rests on its ability to choose the best available, even it it is nor much better than what went before. Lewis Carroll saw how it works. Imagine that we have a three-letter word — lpig' for example — and we want to change it into another — 'sty'. We
can change any letter into any other. U we make random changes and just hope for the best, taking any meaningless set of letters each time, it takes thousands of moves to get the pig into the sty. Natural selection imposes a rule: all the words in between must make sense. It picks up combinations that look good and builds on them. It can get there in just six steps — pig, wig, wag, way, say, sty.

  The theory of evolution caused a sensation in 1859, the year of publication of The Origin, because it seemed to remove the need for a direct link between god and man. The wife of the Bishop of Worcester said of it: 'Let us hope that it is not true — but, if it is, let us pray that it does not become generally known!' After the establishment had recovered from the shock, religious thinkers came up with the idea that evolution was a means to work out God's plan. Even if humans were not perfect, they were perfectible, and selection was how the deity had chosen to do it. However, its action, far from perfecting the imperfect, often seems incompetent or even cruel. Panglossians can find little comfort here.

  Selection can do remarkable things. But much is beyond it. Natural selection cannot plan ahead; it acts, without foresight, taking no thought for the morrow. It does just what is needed and no more, and does it in a slapdash and shortsighted way. It is, to use Richard Dawkins' memorable phrase, a blind watchmaker, achieving an extraordinary end through a simple and inefficient means.

 

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