James D Watson, who co-discovered DNA’s twisted-ladder structure, dies aged 97

Nobel prize winner shaped medicine, crimefighting and genealogy, but later years marred by racist remarks

James Dewey Watson, whose co-discovery of the twisted-ladder structure of DNA in 1953 helped light the long fuse on a revolution in medicine, crimefighting, genealogy and ethics, has died, according to his former research lab. He was 97.

The breakthrough - made when the brash, Chicago-born Watson was just 24 - turned him into a hallowed figure in the world of science for decades. But near the end of his life, he faced condemnation and professional censure for offensive remarks, including saying Black people were less intelligent than white people.