A speaking tour by the DNA pioneer James Watson was thrown into chaos last night when one of Britain's most high-profile scientific institutions announced it was cancelling a planned sell-out appearance.
The Science Museum in London said Dr Watson had gone "beyond the point of acceptable debate" during an interview this weekend in which he claimed black people were less intelligent than their white counterparts.
The 79-year-old American academic, who won a Nobel Prize for his part in unravelling the structure of DNA in the 1960s, had been due to kick off a week-long publicity tour at some of Britain's leading academic institutions, including Oxford and Cambridge Universities, tomorrow by addressing a capacity audience at the museum.
But it said that although the museum was ready to discuss difficult subjects it could no longer act as a platform for Dr Watson's views in the light of his remarks. The scientist, who is director of one of America's leading research institutions, the Cold Spring Harbor Laboratory, had been due to discuss his autobiography, in which he suggests that the notion of " equal powers of reason" across all races are a delusion.
In a statement, the museum said: "We know that eminent scientists can sometimes say things that cause controversy and the Science Museum does not shy away from debating controversial topics.
"However, the Science Museum feels that Nobel Prize winner James Watson's recent comments have gone beyond the point of acceptable debate and we are as a result cancelling his talk at the museum."
The move came as other academic institutions hosting Dr Watson vowed to ensure he faced tough questioning on his views, which have once more opened a debate on race and intelligence considered beyond the pale by the scientific mainstream.
Human rights campaigners called on Dr Watson, a Nobel Prize winner for his role in the discovery of the structure of DNA in the 1960s, to apologise publicly for his comments, describing them as "scientifically unethical and unjustifiable".
Dr Watson is still due to speak at five engagements, including events at the Oxford and Cambridge universities. He will also attend a reception at the Royal Society in London.
But his comments in The Sunday Times have overshadowed the visit and caused an outcry from across the worlds of science, politics and the anti-racism lobby. He said he was "inherently 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 ". The new Human Rights and Equality Commission, which has the power to investigate alleged infringements of race laws, has said it is studying Dr Watson's comments "in full".
Among Dr Watson's appearances will be an event at Bristol's annual Festival of Ideas hosted by the university's vice-chancellor, Eric Watson. A university spokesman said yesterday: "As a university, we respect ... the right of people to express their views. But we would also expect there to be some robust questioning of Dr Watson on his ideas."
Organisers at each of the appearances in London, Newcastle, Edinburgh, Oxford, Cambridge and Bristol said there would be questions from the audience. The co-ordinator of one event, who asked not be named, said: " The correct way to respond is to allow him to be challenged as strongly as possible. A view that is not based on science or is simply wrong will be exposed as such."
Professor Dawkins, who as author of the The God Delusion is no stranger to controversy, yesterday declined to comment on Dr Watson's remarks. The two men, widely considered to be among the world's leading secularists, will appear at Oxford's Sheldonian Theatre next week. Professor Dawkins has previously sprung to Dr Watson's defence after he suggested in a 1997 newspaper interview that a woman should have the right to abort a foetus if it was found to be carrying a "gay" gene. The Oxford academic said Dr Watson was merely speaking in favour of choice for women.
Blink, a London-based human rights organisation for black people, described Dr Watson's remarks as "scientifically unethical, unjustifiable theories [that are] ideologically fudged and bankrupt propositions".
Koku Adomdza, the director, said: "We call on Dr Watson to lodge an unreserved apology to Africa and all people of African origin for his disrespectful remarks and request for the leadership of his university to take appropriate action against him."
CSHL said last night that Dr Watson was unavailable to comment as he was en route to London.