No need to be afraid of genetic engineering

This year is the 50th anniversary of the discovery of the structure of the genetic material DNA by James Watson and Francis Crick. Their work completed the greatest development in biology: the theory of evolution by natural selection introduced by Charles Darwin and Alfred Russell Wallace in 1858. It did so by providing a molecular explanation for evolution.

It also began a revolutionary series of developments at the molecular level in biology. These developments have enormous potential to do good in areas such as medicine and agriculture. As is common after revolutionary developments, however, we remain wary about the promises. In this case also, things are further complicated by the long shadow of eugenics.

Let me mention, as a brief aside, that Ireland played an important indirect role in the discovery of the structure of DNA. This was through a very influential little book called What Is Life? written by Erwin Schrödinger and published by Cambridge University Press in 1944. Schrödinger, who shared the 1943 Nobel Prize in Physics with Paul Dirac, was director of the school of theoretical physics at Dublin Institute for Advanced Studies from 1940 to 1956.

In What Is Life?, based on a series of public lectures he delivered in Dublin, Schrödinger speculated on the physical nature of the genetic material. The book was widely read and attracted many physicists into biology. Watson and Crick have often acknowledged the influence Schrödinger's book had on them.

Before the DNA revolution in the 1950s and 1960s, biochemistry was more or less a single discipline. After the discovery of the structure of DNA, however, some subcategories of biochemistry, such as molecular biology and molecular genetics, grew so strong and popular that they began to regard themselves as disciplines in their own rights. Also, understanding how the elegantly simple structure of DNA underpins its biological activity showed how this structure could be manipulated in the laboratory, which led to genetic engineering and revolutionary forms of biotechnology.

Genetic engineering usually means inserting genes from one species into another to create a novel and useful organism. An example is the insertion of bacterial genes that confer resistance against insect attack into domestic crops, thereby protecting the crops against insects without the need for insecticides.

Another useful development has been the biotechnological production of human insulin by genetically engineered bacteria. The gene for human insulin was incorporated into a bacterium, which was then grown in enormous quantities in vats. The insulin they secrete is harvested and used to treat diabetes.

The DNA revolution has also allowed scientists to determine the structure of many genes responsible for human disease and to map the positions of these genes on the chromosomes. This has led to technologies that allow large populations to be screened for carriers of defective genes. Techniques are also being developed that will allow existing genetic damage to be repaired or replaced by copies of good genes.

People are very wary of molecular biologists' promises about the potential of genetic engineering. Europeans, for example, are generally opposed to genetically modified foods (GMF). There is, of course, good reason to be cautious, but blanket opposition seems to go far beyond mere caution. If only cautious human instinct were involved, how would we explain Americans' relative sanguineness about GMF?

One reason why European opposition to genetic modification is so strong is the legacy of eugenics. Initiated by Francis Galton (1822-1911), it promoted the improvement of the human genetic stock by judicious breeding. It began as a popular and benign idea and gained strong currency in the West. After a while, however, it went off the rails, and sterilisation programmes for mental defectives were introduced in a number of countries. The Nazis enthusiastically adopted - and perverted - eugenics, with disastrous consequences. Ever since, the idea of improvement through genetic modification has received a frosty reception, particularly in Europe.

Both capitalist and socialist ideologies play an important role in popular arguments for and against genetic modification. By and large, the big advances in genetic engineering and the new biotechnologies are now financed and driven by multinational corporations. These corporations, motivated by the need to generate profits for shareholders, will tend, at times, to oversell perceived benefits and downplay possible risks, and consequently they must be closely regulated.

At the other end of the spectrum, there is a strong lobby against GMF that is very effective in the media. A large element of this lobby consists of left-wing activists. The left wing is constitutionally opposed to the new genetics for two reasons. First, it believes, large-scale capitalism can do no right. Second, it fears the day when genes will be shown to determine aspects of human behaviour. This is a highly unpopular concept in left-wing circles, where human behaviour is regarded as socially malleable. The left will tend, at times, to play down perceived benefits and to be overanxious about the risks of the new technologies. Let me add that it is, of course, quite possible to be for or against GMF for reasons other than ideological commitment. William Reville is associate professor of biochemistry and director of microscopy at University College Cork