But there is a snag, churlish though it will doubtless seem to point it out. Steve Jones does not tell it like it is. He writes beautifully and is truly a nice fellow but he is wrong and dogmatic on important matters, including the one that in this context seems closest to the heart of things, which is the communication of science. His treatment of present and future genetics is - and here is the word a radical will not forgive - bland. Scaremongering is distasteful, and the anti-science lobby is irritating. But the potential of modern-day genetics is awesome; and to imply otherwise, as Jones emphatically does, seems positively dangerous. In the Blood is an alluring book and will be wonderful television, an orgy of ostensible scholarship, as Old Testament prophets and mediaeval clerics jostle through thickets of DNA. But what Jones wants, as he says time and again, is peace to get on with his work. He needs public cash but he does not want the public snapping at his heels. And in the end, the rhetoric and imagery of In the Blood are a smokescreen, keeping the commonalty at bay.
For where - and this is the key issue - is genetics leading us? What might be possible? Already, for example, leading medical geneticists are considering gene therapy: the replacement of cells that have malfunctioning genes with cells containing "healthy" genes. Cystic fibrosis is an early target, since the affected cells are near the body surface (lining the lungs) and easy to get at. The human species is beleaguered by several thousand such "single gene" disorders and all of them, in principle, might be tackled.
All this seems very welcome - but what might lie beyond? We cannot draw a sharp line between therapy - correction of obvious ills - and "improvement" - tinkering with what already works well enough. The distinction in the realm of genetics is between gene therapy and eugenics: genetic enhancement of looks, physique, intelligence, or what you will. What might be done? How can we do what is good and avoid what seems disquieting?
In this blockbuster series that seems to be about modern genetics, Steve Jones avoids all such discussion, and effectively derides those who indulge in it. First he tells us that all such musing is old hat. In the old days, he says, people simply assumed inherited characteristics were "in the blood": "blue blood", "bad blood" and the rest. Now, he says, people substitute "gene" for "blood" - but the ideas are the same as before. The specific possibility of eugenics was tried out by the Nazis, and it failed. People who project what may seem to be comparable notions into the future are falling into that same gullible and distasteful trap: thus, says Jones, "Plans for designer babies, eugenic sterilisation, racial classification, are more imagined than real." Indeed, the science of genetics itself is now "facing a more subtle threat; that of public expectations far in advance of reality." Even the potential of preliminary research has been grossly exaggerated: "Its promise of replacing damaged genes ... has been around the corner for a long time. The first claims of a breakthrough were made more than a decade ago. In 1996, there is not one case of a treatment whose success is unequivocally due to gene replacement. The rewards promised so confidently have not materialised and show few signs of so doing."
Yet this last phrase, taken from In the Blood, simply is not true. There are many signs that gene therapy, at least for the simplest single-gene disorders, will be with us within a few decades. If success has not been achieved in the past ten years, so what? A decade is ludicrously short. In another mood we could state the matter in entirely the opposite fashion, for what is surely most striking about genetics is the sheer pace of advance. Genetics itself - the very word - is a 20th-century creation, since Gregor Mendel's 1860s pioneer experiments were forgotten until the early 1900s. The most elementary fact - that genes are made of DNA - was established only in the 1940s: before that, most biologists assumed they were made of protein. DNA structure was only unravelled in the 1950s, by Francis Crick and James Watson. Only then did the abstract "gene" become a chemical reality; only then did we hear the expression "molecular biology". The notion that genes could be transferred from one organism to another in a functional state - "genetic engineering" - dates only from the 1970s. Yet "engineered" or "transformed" microbes have already raised the traditional crafts of industrial microbiology to the heights of present-day "biotechnology"; several multinational companies would be very surprised to be told otherwise. Genetically transformed crops are already grown commercially.
In short, intervals of two decades have so far taken us from one conceptual phase into the next. The notion that we might soon manipulate defective genes in human beings seems positively modest - provided, that is, we define "soon" realistically: not next week, or even next decade, but certainly within the next half century. Indeed within a few hundred years - a twinkling in the history of humanity - our control over the processes of life will become effectively absolute. The creation of life in some form or other will surely be possible within 100 years, and considered routine the century after. Those who deride such speculations do so at their peril. In a book review in The Independent, Steve Jones's fellow professional guru (and my fellow contributor to these pages), Lewis Wolpert, dismissed the possibility of human cloning. "There is not the slightest evidence that this can be done for any animal and while one cannot predict the future, at present it is almost as unlikely as building a time machine," he wrote in November 1993. You would have to be living in a time machine not to know that this has now been done in sheep; and in 1993, preliminary work was already well advanced.
Overall, we can reasonably suggest that anything that does not break what Sir Peter Medawar called "the bedrock laws of physics" is liable to become feasible in the fullness of time. (Time machines would, of course, forever be implausible precisely because they would break those laws.) Jones's (and Lewis Wolpert's) understatements, and their derision of those who seek to speculate, are at best only partly justified.
On the theoretical front, there seems to me to be a serious omission in both Jones's book and his programme. The most momentous lines of inquiry in modern genetics lie not in gene therapy or even life creation, but in the understanding of behaviour. Underpinning this is the notion of what Richard Dawkins has called "the selfish gene"; the idea that natural selection is focused primarily not on individuals (as Darwin supposed) and still less on populations as a whole (as some of Darwin's successors maintained) but in individual genes: individual codes that underlie individual features, including features of behaviour.
Why is this idea so pivotal? After all, a gene does not survive in isolation but only as part of an organism. It follows that a gene cannot survive in the long term except by favouring the organism of which it is a part. So in practice, it surely makes no difference whether we say that natural selection favours individuals who are the "fittest" (where "fit" means "apt" as in the Victorian sense), or favours the particular genes that contribute to their fitness.
Well, "selfish" genes in general do promote their own survival by abetting the creatures that contain them. But, interestingly, sometimes they do not. Genes have their own agenda. They will promote their own propagation in the short term even if they compromise the creatures that contain them in the longer term. They are not simply selfish. They are completely solipsist: blind, deaf and unaware. The idea that genes pursue their own agenda offers us a chance to look at the currents that lie beneath our actions and ostensible motives, but Jones doesn't do justice to these modern insights. He deals competently with ideas relating to "genes for aggression" or "genes for intelligence", but those notions are already somewhat passe. We have moved on. Of particular importance is the work of Bill Hamilton, now a professor at Oxford, who has pointed out, however odd it may seem, that irredeemably "selfish" genes may succeed by promoting behaviour which is "altruistic". In the interests of brevity, we can talk of genes "for" altruism; all populations of animals possess them. A gene for altruism is any gene that codes for any particular character - not necessarily a behavioural feature, although behaviour is most obviously implicated - that is costly to the individual who owns that gene, but is beneficial to the creatures around it. Examples abound: such genes are at work in any field of rabbits, flashing their white tails as they run from danger to warn their fellows, even though it would be far safer simply to sneak away and leave them to it.
Such behaviour is genetically endowed. Natural selection has favoured the solipsist genes that bring it about. How? Because the other animals that are being warned are likely to be related to the one that blows the whistle, and are therefore likely to contain copies of the same altruistic gene that prompted the apparently selfless behaviour. The point is not that the whistleblower calculates the odds that others contain the same gene as itself. The point is that if an altruistic gene arises in a population then, by promoting altruistic behaviour, that gene will propagate its own spread, because it will promote the survival of others that contain copies of itself. In short, selfishness and altruism are not antithetical: the altruism is an expression of the selfishness. The inevitability of altruism in what in essence is a ruthless world is one of the many notions of science that can be difficult to grasp precisely because it is so simple. But its ramifications are huge.
For example, Hamilton himself has suggested that - biologically speaking - parental care is merely a special case of more general "altruism": parents favour their own children just because those children have the greatest chance of containing (altruistic) genes like their own. Extrapolations of such themes predict that females have a different "agenda" from males, and hence pursue different strategies: females furthering their own genes by ensuring survival of the relatively few children that they are able to produce, and males doing most to propagate themselves by increasing the number of offspring. The point is not to declare that what is "natural" is thereby "right": "is" is not "ought", as David Hume pointed out in the 18th century. Immanuel Kant made the point more strongly: that what is natural would obviously come easily and what comes easily cannot be said to be "good" at all. But it certainly helps, in all discussions of morality, and in all exercises in sociology, to know ourselves. The modern genetics of behaviour does just this, exposing and analysing the genes which, in their own interests, are nudging us this way or that even when we suppose that we - our conscious selves - are fully in command of our actions, or at least of our thoughts. In so doing, this new science ventures into territory that once seemed to belong exclusively to literature. George Eliot would have loved these musings.
Jones spends much of In the Blood discussing the genetic underpinning of human behaviour. He told me: "I may not like everything that genetics finds out about ourselves. But if it turns out to be true, I will go along with it. We should not curtail research. We should find out what it has to tell us, and learn to live with whatever turns out to be the case."
Furthermore, he exposes the poverty of thought that has lain behind some of the recent claims for "behavioural genetics": the alleged genes "for" criminality that have provided fatboy Southern sheriffs with a new excuse for hanging blacks. He shows the two-edgedness of modern science, in this forensic context: for some have tried to defend their clients' aberrations on grounds of diminished responsibility, since their genes caused them to behave badly, while others suggest that those with built-in behavioural flaws should be done away with, to protect the rest of us. On this point Steve Jones is right and subtle. As he says in In the Blood: "There can be no universal excuse for bad behaviour. If some are excused because of their genes, then others, with a different constitution, must be more culpable ... For the law to survive it must ignore the defence of original sin, inherited frailty, in much the way that it ignores poverty, inborn or not."
So why should anyone object to Jones's treatment of "behavioural genetics"? Because the ideas that he describes belong in the main to an earlier conceptual era, when people focused on genes "for" broad human qualities such as intelligence, or aberrations like aggressiveness. Much of that early work was crude. The insights that could emerge from the far more precise predictions of Hamilton and his confreres are altogether more robust and more profound: dealing not specifically with our aberrations, but with our normalcy, with the elusive quality of "human nature". Steve Jones's comment in his book that "altruism always fails in the face of self-interest" suggests that he has missed the point. By not exploring this concept further, he is effectively ignoring 20 years of theory and of ever-growing observation.
Why does this matter? Because it deceives, by giving the impression that the modern genetics of behaviour has to do with criminality and IQ, where in fact it has moved far beyond that; and because Jones suggests that the new ideas are enfolded in the ideas of the past, while in truth they are qualitatively different; and because, by giving the impression that the new work is all old hat (as he also suggests is true of eugenics), he diverts disquiet. The message is that we have been down this path before, and nothing has come of it; so nothing will come of it in the future. This argument in several ways, is false and dangerous.
SO, FINALLY, to the all-pervasive irony. Ever since doing the BBC's prestigious annual Reith lectures, Jones has been promoted as the arch- expositor of science; a veritable guru. This is not of his seeking - "the Reith lectures came out of the blue" - but it is the case. Yet he said in The Guardian and defended the comment to me, that the popular presentation of science is an "ignoble" pursuit, tantamount to science "pornography", and innately inferior to the practice of the research which he would love to get on with if only the telephone would stop ringing. Such a view seems to me again profoundly and dangerously untrue.
For in Britain at least, "the two cultures" that CP Snow described in the late 1950s are with us still. Still the most expensively educated are split between those who do science, and those who see its practitioners as "northern anoraks", and delight in telling the rest of us (as you can read in any review of any TV science programme) how their minds shut down when they hear the word "relativity". Though many scientists, including Jones, are people of broad culture, they seem in many ways to promote this dichotomy. In British schools and universities, science for the most part is still presented as an apprenticeship, as if the only point of it were to mould professional scientists. Hundreds of hours are spent in "practicals", polishing techniques that will never be used again. Little is said of the philosophy of science, although the philosophy - by which I mean all the embracing ideas - is in many ways wonderful. Largely because of this sheer philistine grind, many of the cleverest people are driven into classics or English - where, as Peter Medawar again pointed out in mischievous vein, they find "they have nothing to be clever about". What matters even more is that people are not introduced in the general course of education to the delights and the portent of science, precisely because science is not treated as a natural part of our culture but as a metier like, say, basket making, which you either learn for professional reasons or ignore.
This matters culturally, because it is a shame to go to the grave without knowing the delights of science's insights. It also matters politically, because science and the technologies it generates are in the end the most potent agents of social change. The general failure to understand what they can do seems a mockery of democracy. If people had a broad background in science, then the journalism of science would be needed to keep the momentum going, for few of us have the time or opportunity to read the specialist journals. In the absence of such a general background, the "popular" literature of science is doubly important since for most, this is all the information they will ever receive.
The journalism of science in Britain is in a primitive state. Every significant human activity - politics, arts, sport - has its coterie of critics and commentators. Some are themselves practitioners and others are informed outsiders - journalists - and that is how it should be. Britain has no shortage of excellent science journalists; generally people who read science at university and then decided that the ideas were, in the end, more alluring than the practicalities of research. But in Britain at the moment a few practising scientists have come to be regarded as the acceptable "voice" of science; and, like medieval priests, they rest upon their authority. The undesirability of this becomes clear if we draw a parallel with politics: it is as if we had taken no interest in state affairs since the 17th century and now, rediscovering their significance, had decided the only people qualified to comment on them were Michael Heseltine and John Selwyn Gummer.
But is the analogy fair? Not, perhaps, if the scientists tell it like it is. But scientists, like all of us, have their own agenda. On the whole, they want to get on with their work. We only stay off their backs so long as we believe that what they are doing is important and difficult - no distractions, please! - and so long as their work seems unthreatening. Imply, therefore, that nothing much is going on: that speculation is silly, and that everything happening now has happened in spirit in past times and will soon be enfolded once more in the clouds of history, like all past excesses.
This message is misleading. This is a new age. The new genetics is changing everything. If only in the interests of democracy, we should all reflect on its implications. In the Blood does not advance our deliberations. It merely serves to postpone them.
Steve Jones's series 'In the Blood' begins on 13 May on BBC2 at 8pm. The book of the series is published by HarperCollins at pounds 20.