At the beginning of 1900, no biologist had conceived of the gene. Now, in 2000, the first draft of the human genome has just been finished. In the spring of 1900, the work of a Moravian monk, Gregor Mendel, on inheritance in peas was rediscovered. In a series of elegant experiments 40 years earlier, Mendel had shown that an organism's characteristics are passed from one generation to the next as discrete units - what would later be called "genes". Mendel was the genius whose work was ignored until accidentally rediscovered at the dawn of the 20th century. The rediscovery of Mendel and his laws of inheritance helped to establish the discipline of genetics and set us on the road to the human genome project, the completion of which, according to James Watson, the co-discoverer of the structure of DNA, will tell us "how life works".
That is the conventional story of the history of genetics and of its contemporary importance. Robin Henig and Richard Lewontin dispute conventional wisdom at either end of the tale. A Monk and Two Peas is a reconsideration of the role of Mendel in the development of genetics, while It Ain't Necessarily So sets out to debunk contemporary myths about the role of genes in our lives.
A Monk is not a particularly original work; most of the material here is well known. But it is a lucid, popular biography, which is alive to new trends in historiography. In recent years, the "Great Man" view of science - the belief that science is an endeavour pursued by isolated geniuses - has given way to an attempt to understand science in its social context, to see both scientists and their ideas as products of their times. Henig shows how the myth of Mendel as a tragic hero, ignored because the world was not ready for his ideas, was created by early 20th- century biologists as part of the process of building the discipline of genetics. Every science, she argues, needs a hero, someone "on whose giant shoulders his disciples can stand". Because little was known about his biography, and because what was known was largely admirable - a solitary, devout, dedicated soul - Mendel was an "ideal tabula rasa on which latter-day Mendelians could etch a tale that it pleased them to think was true".
At the same time, Henig chides those revisionist historians who want to dismiss Mendel's importance to modern genetics. Some recent historians have argued that Mendel was never looking for the laws of inheritance; that he was just trying to breed better and more reliable flowers, fruits and vegetables. This, too, is a form of myth-making, Henig believes. Mendel could not have been turned into the founding father of genetics "if it were not for the much more critical point: Mendel was right".
If geneticists of a hundred years ago strived to create myths about the origins of their discipline, contemporary geneticists try to do so about the object of their study. In recent years, behavioural geneticists have claimed to have discovered genes for, among other things, aggression, alcoholism, ano-rexia, anxiety, attention-deficit dis-order, autism, extroversion, heroin addiction, homosexuality, intelligence, impulsiveness, introversion, manic depression, obsessive compulsive disorder, sadness, schizophrenia, social skills and thrill-seeking. "We used to think that our fate was in our stars," James Watson said. "Now we know, in large part, that our fate is in our genes." It Ain't Necessarily So is an elegantly written and lucidly argued critique of the myth that genes are fate.
Lewontin is one of the great unsung figures of postwar science. A brilliant geneticist, he invented in the 1960s a technique for measuring variation in genes, and used it to demonstrate that populations are much more variable than previously thought. Equally important have been his attempts to elucidate the philosophical and methodological problems of genetic research. Lewontin's latest book is a collection of essays on the theme of evolution and genetics written for the New York Review of Books. Collections such as this are often bitty and incoherent. Not so in this case. Few writers, and even fewer scientists, possess Lewontin's strength of vision, breadth of knowledge or stylistic poise.
Yet, in an age when many evolutionary biologists and geneticists are household names, Lewontin is barely known to the wider public. The reason is that his arguments, both scientific and politi-cal, are deeply unfashionable. Two great intellectual struggles have framed his life - for Marxism and against sociobiology. In both, the tide has been running strongly against him.
As Marxism has self-destructed in recent years, so Darwinian explanations of life, the universe and everything have become ever more persuasive. In fact, the two processes are closely connected. The collapse of Marxism, the blurring of distinctions between the left and right, and the disintegration of working-class and other oppositional organisations have transformed the nature of political debate and, in the eyes of many, made politics irrelevant to their lives. They have also made irrelevant the dominant social explanations of human behaviour, most being rooted in, or having developed from, Marxism. These changes have loosened social bonds, creating more atomised societies, and have put under great pressure traditional moral codes and social values.
In this age of uncertainty, when many people feel a sense of alienation both from social institutions and from one another, evolutionary theory provides a form of anchorage. It gives people a sense of who they are, where they have come from and where they are going.
The Darwinian philosopher Michael Ruse wrote that "our moral ideas are thrust upon us . . . as a function of our biology", rather than as "being things needing or allowing decisions at the individual level". He added: "We are not free to choose what right and wrong are to be. Where freedom comes, if it is to come at all, is in working within the given bounds of right and wrong." Freedom arises out of our being "conscious agents, aware of the dictates imposed by [biology]". His argument is similar to the old Christian belief that reason and morality are created by God and that freedom lies in becoming conscious of God's will. The main difference is that, in Ruse's model, God has been replaced by Nature.
Lawrence Wright, in his book Twins, concludes that behavioural genetics "has made a persuasive case that much of our identity is stamped on us from conception; to that extent our lives seem to be pre-chosen - all we have to do is live out the script that is written in our genes". That is truly a remarkable way of understanding what it means to be human - an almost medieval notion at the beginning of the 21st century. Over the past century, science has advanced tremendously in its grasp of genetics, but it also seems to have regressed in its understanding of humanity.
It is against this background that we should read It Ain't Necessarily So. However unfashionable Lewontin's arguments may be, his ideas remain important for anyone wanting to make sense of contemporary biology, not because he is always right (he often isn't), but because he provides a necessary corrective to the facile character of much contemporary thinking about evolution, genetics and human nature.
Three themes underpin Lewontin's view of science and give coherence to his work. The first is his recognition of the importance of philosophy to science. The problem of much contemporary science, he writes, is that "we do not know how to produce well-framed questions of whose relevance we are sure". As a result, "we have faddish models that succeed each other at five- or ten-year intervals, driven largely by changes in available technology in other branches of science, rather than any coherent intellectual programme".
The second theme is Lewontin's appreciation of materialism. Sociobiologists and evolutionary psychologists often dismiss their critics as anti-materialists. If you don't believe that human behaviour can be understood in natural terms, they argue, you must posit the existence of God or some other non-material force. Lewontin insists that he is entirely materialist, while arguing that the material world is not the same as the natural world. A materialist explanation of what it means to be human must take into account historical and social developments, too.
Lewontin's third theme is his understanding of science as a social activity. Scientists, he argues, are social actors and, as such, they and their ideas are deeply influenced by social ideologies. The impact of these three themes taken together is to give Lewontin a much more sceptical view of contemporary science than most of its practitioners, especially natural scientists, possess. This allows him to demystify contemporary ways of thinking about nature and human nature. But sometimes it can make his analysis seem surprisingly naive. His discussion, for example, of the ideological roots of reductionism and of biological determinism, both in this book and in his other works (such as Not In Our Genes, co-authored with Steven Rose and Leon Kamin), is itself reductive and crude.
Lewontin's scepticism sometimes makes him blind to the possibilities of scientific advances. Take, for instance, his discussion of the human genome project. He rightly castigates the idea that sequencing the human genome will make us understand better what it is to be human, or engender a "change in our philosophical understanding of ourselves", as the biologist Walter Gilbert predicts. Such grandiose claims rely on a near- mystical understanding of the role of DNA in the creation of who we are.
But Lewontin's desire to demolish the mystique of DNA leads to an unwarranted pessimism about the possibilities of the project as a whole - which, he suggests, is driven by administrative and financial considerations rather than research ones. And, Lewontin believes, the consequences will be largely negative and ideological: "The importance of the human genome project lies less in what it may reveal about biology, and whether it may in the end lead to a successful therapeutic programme for one or other illness, than in its validation and reinforcement of biological determinism as an explanation of all social and individual variation."
This seems a strange dismissal, not only of the medical possibili-ties opened up by the project - the prospect, for instance, that we may one day find a cure to single-gene conditions such as muscular dystrophy or cystic fibrosis - but also of the significance of the project as a human and scientific landmark. Landing a man on the moon was enormously expensive; the consequence of cold-war politics, it had no immediate practical benefits. Nevertheless, it was a significant and magnificent human achievement. The same is true of the project to unravel the human genome - the book of life itself.
Kenan Malik's Man, Beast and Zombie: what science can and cannot tell us about human nature is published by Weidenfeld & Nicolson in October