A Nobel Prize-winning scientist who provoked a public outcry by claiming black Africans were less intelligent than whites has a DNA profile with up to 16 times more genes of black origin than the average white European.
An analysis of the genome of James Watson showed that 16 per cent of his genes were likely to have come from a black ancestor of African descent. By contrast, most people of European descent would have no more than 1 per cent.
"This level is what you would expect in someone who had a great-grandparent who was African," said Kari Stefansson of deCODE Genetics, whose company carried out the analysis. "It was very surprising to get this result for Jim."
The findings were made available after Dr Watson became only the second person to publish his fully sequenced genome online earlier this year. Dr Watson was forced to resign his post as head of a research laboratory in New York shortly after triggering an international furore by questioning the comparative intelligence of Africans. In an interview during his recent British book tour, the American scientist said he was "inherently gloomy about the prospects for 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 Science Museum in London cancelled a lecture by him, while the Mayor of London, Ken Livingstone, branded his comments "racist propaganda".
Other scientists working in the field of molecular biology quickly distanced themselves from the comments, saying that it was not possible to draw such conclusions from the work that had been done on DNA.
The study of the DNA of Dr Watson who shared the 1962 Nobel Prize for medicine adds another twist to the controversy surrounding the American scientist's comments.
In addition to the 16 per cent of his genes which were identified as likely to have come from a black ancestor of African descent, a further 9 per cent were likely to have come from an ancestor of Asian descent, the test indicated.