Flavr of the Month

Daniel Kevles

  • Perilous Knowledge: The Human Genome Project and its Implications by Tom Wilkie
    Faber, 195 pp, £14.99, May 1993, ISBN 0 571 16423 4
  • The Language of the Genes: Biology, History and the Evolutionary Future by Steve Jones
    HarperCollins, 236 pp, £16.99, June 1993, ISBN 0 00 255020 2

Nothing in contemporary science seems to trouble the public more than genetic engineering. Despite the cloying sentimentality that Steven Spielberg has introduced into Jurassic Park, the film expresses the sharp scepticism about the benefits of manipulating DNA that forms the moral core of the novel by Michael Crichton on which it is based. In the novel, Ian Malcolm, the conscience of the tale, remarks as he lies dying from a raptor attack (in the film he doesn’t die; only villains die on Spielberg’s screen): ‘Science, like other outmoded systems, is destroying itself. As it gains power, it proves itself incapable of handling the power.’ According to a recent poll, a substantial majority of Americans believe that the risks of genetic engineering outweigh the benefits.

Since the discovery of recombinant DNA – the technique for slicing genes from the cells of one species and inserting them into the genetic strands of another – the risks that have drawn the most attention have had to do with the environment and public health. Activists have contended, for example, that bacteria engineered to contain a gene to make plants resist frost better might contaminate the wild population, with unpredictable and, probably, adverse consequences. The imminent arrival in the food shops of genetically-engineered vegetables – notably, in the United States, the Flavr Savr tomato – has provoked threats of a boycott of any food-processing company that uses them and pledges from almost two dozen leading American chefs that they will not allow genetically altered food into their kitchens.

These apprehensions about bugs and plants and animals have a subtext: what can be done with such organisms today, including with dinosaurs on film, might be done to human beings tomorrow. History unfortunately provides a precedent: the eugenics movements of the first third of this century, when various scientists and social engineers proposed to improve the quality of the human race by encouraging people with ‘good’ genes to proliferate and discouraging those with ‘bad’ genes from procreating at all. These presumptions were scientifically ludicrous and rooted in social prejudice: eugenic theorists took race and socioeconomic class as proxies for the possession of ‘good’ or ‘bad’ genes. Among the measures proposed was forced sterilisation, which was adopted as government policy in a number of American states (although it was enforced in only a few). In Nazi Germany, eugenics produced several hundred thousand sterilisations and was one of the factors that led, ultimately, to the death camps.

It is no surprise, then, that a common element in the disquiet about genetic engineering is that what is most at risk is us. The eugenic ideal, which has been around in Western cultures at least since Plato, continues to tantalise some. Indeed, in the Sixties, when the genetic code of DNA was worked out, biologists here and there began calling for a new but sanitised eugenics, for human biological engineering free from racial and class bias and devoted to genuine improvement of the species and its members. In point of fact, only in recent years have techniques become available to make the analysis of human heredity at the level of DNA practical and rewarding. At the end of the Eighties, the new tools of molecular genetics were recognised as sufficiently powerful for a major enterprise to be mounted that would locate and identify all the one hundred thousand or so genes that comprise our genetic essence. The Human Genome Project has support from a number of governments, including those of Britain and the United States. It is advancing rapidly on the scientific front – and raising a variety of social spectres, including the ‘fear’, as Tom Wilkie writes in Perilous Knowledge, ‘that the project may open the door to a world peopled by Frankenstein’s monsters and disfigured by a new eugenics.’

Wilkie, a physicist turned science journalist, provides a lucid, serviceable primer on the technical developments that have made the Human Genome Project possible and on the social challenges it poses. As such, his book joins a substantial shelf of popular volumes on the subject, several of which he appears to have borrowed from. What makes his book distinctive is its attentiveness to the British situation and to current debates about race, access to medical care, and the moral implications of scientific and technological change.

Steve Jones’s The Language of the Genes devotes some space to the Genome Project and its implications but treats it as part of a broad disquisition on ‘what genetics can – and cannot – tell us about ourselves.’ Jones, a malacologist (which is to say, he works on molluscs) and Professor of Genetics in the Galton Laboratory at University College London, is sensitive to the social issues raised by genetics. Francis Galton was the founding father of modern eugenics, and a glass case of Gaitonian relics in the UCL laboratory reminds passers-by of their institution’s paternity. Yet Jones’s interest reaches beyond contemporary social issues to the human past, to what genetics can and cannot tell us about our evolution and patterns of social development. He interleaves a broad knowledge of biology with considerations of cultural, demographic and – as his title indicates – linguistic history. Based on his 1992 Reith Lectures, Jones’s book is at once instructive and captivating.

The total complement of human DNA is spread through 24 chromosomes, including 22 autosomes (so called because they are independent of sex) and two sex chromosomes, X and Y, each named after its shape. As both authors explain, though Wilkie in much greater detail, the aim of the Human Genome Project is to create a physical map of the DNA on each chromosome: to slice the DNA into fragments, determine the order in which the fragments occur, and obtain the sequence of molecular coding (the base pairs that link the two strands of double-helical DNA) at each point. It is also to create a genetic map of each chromosome – i.e. to determine the relative location of each of the genes it may contain. The final intention is to merge the physical and genetic maps, so that the precise physical location of the gene will be known, as well as its molecular codes.

The overall task is daunting: estimates put the number of genes in the human genome at between fifty and a hundred thousand and the number of base pairs at three billion. The United States, which was the first country to commit itself to the project, expects the cost to run as high as three billion dollars, spread over fifteen years. It is said to be bringing biology into the orbit of Big Science. Wilkie likens the project to the Apollo programme, which put men on the Moon, but the analogy is not strictly relevant, since Apollo cost perhaps forty times as much in inflation-adjusted dollars and was centrally directed to achieve a special technological goal. The Human Genome Project’s task includes developing mapping and sequencing methods that will speed up the project and reduce the costs, but its major goal is information: the complete map and sequence of the human genome. Once achieved even in part, the information can be exploited to understand disease, design drugs for therapy and cure and assist in analysing human development, behaviour and evolution.

According to Wilkie, it was the worry that a purely American effort would give the United States a strong advantage over British science and the British pharmaceutical industry that prompted the British Government to create its own genome project. This won the early support of Mrs Thatcher, and has been insulated from the ferocious competing demands on the national science budget. Now the recipient of approximately £20 million a year, it ranks second behind the American project both in financing and scientific productivity. The British have set their technical sights on mapping and sequencing only those stretches of human DNA that actually code for genes. These stretches, found at random intervals along the DNA strands, can be likened to tiny islands of meaningful information set in a linear sea of nonsense. These coding versions are estimated to occupy only 5 per cent of the human genome. Scientists call the other 95 per cent ‘junk DNA’. The British strategy is risky, since what fraction of DNA is significant can only be determined experimentally. However, to offset the risk, British scientists are first mapping and sequencing a much simpler organism (the worm c. elegans) to see what percentage of its DNA actually codes for genes.

Because the Human Genome Project will lead to new knowledge about human genetics, the first social issue that it forces society to face, Wilkie writes, is ‘the handling of that knowledge: who has a right to own information about human DNA and who should have access to that information’. Some of the early indications have been troubling. The American National Institutes of Health (NIH) have attempted to obtain patents on a raft of human genes about which its scientists know about as much as one might about a chest of treasure buried in the ground, only a small corner of which is visible. The implication, according to Wilkie, is that, in the view of the NIH, ‘the human genome, the innermost essence of humanity, is just another resource for commercial exploitation.’ In fact, many scientists in and outside the biotechnology industry have protested against any granting of such patents and the US Patent Office recently rejected the application.

Wilkie himself acknowledges that the patent issue is, in any case, a minor one compared with other social issues that surround the Genome Project. The increasing acquisition of genetic information about human disease will confront those whose families have a history of such diseases with anxious choices: whether to have themselves tested for an adverse gene; whether, if they have a particularly bad one, to risk bearing a child; whether to ascertain if their foetus is afflicted with a combination of genes that will doom or debilitate the child, when the only ‘therapy’ for a positive result is abortion. Wilkie regrets the invasion of technology into the way people feel about themselves and each other but a growing number of people are, nevertheless, making use of this information, it only because the law and medical ethics compel doctors to make it available to them. At least the British health care system appears better equipped than the American one to deal with the problems that acquiring such information can raise for individuals and their families. Then too, American health insurers may demand a genetic profile of applicants, with an eye to denying insurance to those at high risk or to charging excessive rates for its provision. National health care by its very nature admits everyone to the system, thus avoiding such inequities. The cost of treating some genetic diseases can be very high, and the more the cost of health care rockets, the more even national health systems may be tempted to ration benefits.

Wilkie is concerned that the growing emphasis on the genetic basis of disease will overshadow attempts to ferret out its environmental causes. Genes are necessary to the governance of organisms but they are not sufficient for their healthy development and maintenance. Sound nutrition is as essential to the growth of the child as a sound constitution. The point is a sensible one, and should be well taken. However, Wilkie neglects what should be stressed equally – that finding disease genes fingers undiseased ones, which in turn provides a purchase on understanding what makes an organism go right as well as wrong. Jones, strongly mindful of the fact that organisms are the product of genes and environment, points out that once the defect in a gene is identified and understood, the environment can in principle be adjusted to compensate for the genetic deficiency.

Still, the benefits of human genetics, like those of virtually all other forms of medical high technology, are embedded in a health system that is inequitable with regard to class in the advanced countries and between the advanced and the developing world. Although the Human Genome Project is not responsible for those inequities, its results could well intensify them. The designer drugs it inspires will probably be more readily available to the affluent, just as all costly drugs already are. And affluent prospective parents will be better able to take advantage of technologies choosing genetically advantaged offspring, if such technologies become available.

Wilkie worries that as the project reveals ever more human genetic differences, it may generate new forms of discrimination, or that current types of ‘discrimination may find new and specious justification in the language of biological determinism.’ It won’t, however, be possible to use any such ‘justification’ against groups, especially racial groups, because one of the striking consequences of recent advances in human molecular genetics is the revelation of how much seemingly disparate groups have in common genetically. Jones writes: ‘The biology of human race has nothing to do with the issue of racism. Modern genetics does in fact show that there are no separate groups within humanity (although there are noticeable differences among the peoples of the world).’ Elsewhere he adds that ‘a race, as, defined by skin colour, is no more a biological entity than is a nation, whose identity depends only on a brief shared history.’

Jones explores at length what Wilkie only notes: that growth in knowledge of molecular genetics will provide an enormous array of information bearing on human evolution and settlement patterns. Reconstructing human evolution from anatomical fragments, Jones remarks, can ‘never be much more than clutching at straws (or perhaps jaws)’. But genes provide another window onto the past, since ‘the connections between humans and primates are preserved in the DNA of living animals,’ and ‘molecular biology is just anatomy writ small.’ Similarly, the small circles of DNA called mitochondrial DNA are passed onto succeeding generations only through females. The geographical pattern of shared mitochondrial types among African pygmies indicates that historically the women stayed close to their villages while the men roamed, spreading their genes widely.

Genetics puts prevailing ideas about human migrations to the test. Jones reports, for example:

There are very few genetic links between the people of the Pacific and those of South America. Thor Heyerdahl’s book of his daring voyage in a balsa raft across eight thousand miles of Pacific from Peru has sold twenty million copies, probably more than all other anthropology books put together. Unfortunately, his view that to reconstruct the past it is only necessary to re-enact it is wrong. Population genetics has sunk the Kon-Tiki.

A comparison of molecular DNA sequences across different groups suggests that isolation, which also produces linguistic evolution, has produced genetic variation as well. Jones writes that ‘family trees of language look so similar to those based on the sharing of genes as to suggest a common history,’ adding that languages tend to retain ‘enough of their identity for long enough to be, like genes, clues about the past and about the history of barriers to mating.’ Barriers to the mixing of languages and genes can occur even within countries. In France, for example, there is a small genetic step between those who speak the French of the South and the French of the North.

Both Jones and Wilkie emphasise that organisms are more than just their genes. As Jones puts it, the outlook of Galton and his successors that ‘there are no people, there are only genes’ is as hazardous and indefensible as Mrs Thatcher’s statement that ‘there is no such thing as society, there are only individuals.’ And both urge, by extension, that all organisms be treated as multi-dimensional, holistic entities endowed with their own purposes. Jones holds that genetic engineers will probably not be able to produce Frankensteins even if they want to, and is sympathetic to genetic engineering, thinking that its pharmaceutical and agricultural benefits will be abundant. Yet bearing the effects of chemicals like DDT in mind, he reminds us that ‘the triumph of human ingenuity has not been unalloyed,’ and that ‘because living organisms can deal with new challenges by evolving to cope, genetic engineers, unlike those who build new bridges, must face the prospect that their new toys will fight back.’

The increasing evidence of genetic similarities between human and animals prompts Wilkie to hope that people will learn to treat animals more humanely once they recognise their kinship with ourselves. However, Jones notes that even though we share more than 98 per cent of our genes with chimpanzees, that does not make the chimp any more human (or us any less so). No ‘ought’ follows from this scientific ‘is’. More important, as Jones wisely recognises, ‘science has nothing to do with how we perceive or treat our fellow human beings.’ All such matters are issues of morality, for which science is merely enlisted on one side or the other.