When Nobel prize winner James Watson made racist comments about black people and intelligence last month, he was using his scientific credentials to legitimise bigotry.
It has been said that if the 20th century was the age of the atom, the 21st century will be the epoch of the gene. With the completion of the human genome project we are offered a future in which the genetic basis of disease has been fully worked out and medical treatment is tailored to each individual.
Of course the reality is that conditions such as cancer and heart disease, never mind mental "illnesses" like schizophrenia and depression, most likely involve a complex interaction between genes and environment. It also seems premature to talk about a brave new world of personalised medicine when many of the world's population still cannot afford the simplest drugs.
Nevertheless, for a biologist like myself who studies the role of genes in conditions as diverse as infertility and diabetes, now is an exciting time to be carrying out medical research. As a lecturer at Oxford, I also hope to pass on my enthusiasm to my students, one of whom is a talented young black woman who originally comes from Nigeria.
In our first tutorial, we began by discussing the people who initiated the molecular biology revolution, in particular Francis Crick and James Watson, who in 1953 discovered the "double helix" structure of DNA.
It came as a shock a week later to hear that Watson, on the eve of a trip to Britain to publicise his new book, was quoted as saying that he was "gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really". He added that while he wished everyone was equal, "people who have to deal with black employees find this is not true".
The fury that greeted these racist comments led the Science Museum to cancel an event at which Watson had been due to appear. As campaigns were set up to oppose him speaking at other institutions, he cancelled his tour and flew back to the US to address the furore that his comments had caused.
Watson himself has now apologised for his words, but there is no indication that he was misquoted and his apology sits uneasily with the claim he makes in his book: "There is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so."
The fact is that Watson's views have no scientific validity. His claims about intelligence are presumably based upon studies such as the one carried out in the 1990s in the US which found that black students scored lower on standard IQ tests than the general population. However, such tests are notoriously biased towards white middle-class forms of knowledge.
The claim that Africa's current troubles are due to lack of intelligence on the part of its inhabitants, and not to centuries of imperialist pillage and post-colonial intervention, does not easily fit with the fact that the scientific methods upon which civilisation is based were first developed in Africa.
Meanwhile, the human genome project itself has laid to rest the idea that there are significant differences between so-called racial groups. It showed that humans share 99.9 percent genetic similarity, and that there is greater genetic variation within each race than there is between races.
Some have argued that cancelling Watson's lectures is censorship. But Watson is not some isolated individual. He is a key figure in the scientific establishment. As a major player in the National Institutes of Health, the main funding body for medical research in the US, he must have influenced the careers of thousands of US scientists.
It is a scandal that while blacks make up 12 percent of the US population, they only occupied 1 percent of senior positions in the top science institutions in the country in 2002. For Watson to be allowed to get away with his racist outburst would send a signal that this state of affairs is not the consequence of discrimination and lack of educational opportunities, but the fault of black people themselves.
Of course none of this should detract from the magnitude of Watson's scientific achievements. With this in mind, I agree with the words of Mike Botchan, co-chair of the molecular and cell biology department at the University of California, Berkeley, who has known Watson since 1970.
He recently said this about him: "Is he someone who's going to prejudge a person in front of him on the basis of his skin colour? I would have to say, no. Is he someone, though, that has these beliefs? I don't know any more... I think Jim Watson is now essentially a disgrace to his own legacy. And it's very sad for me to say this, because he's one of the great figures of 20th century biology."
Dr John Parrington is a lecturer in molecular pharmacology at the University of Oxford