James D Watson, the Nobel Prize-winning biologist whose discovery of the DNA double helix with Francis Crick transformed science, and whose later remarks on race and genetics drew condemnation from the global scientific community, remains one of the most polarising figures in modern biology.

Watson's 1953 discovery revealed the structure of DNA, the molecule that carries hereditary information, paving the way for genetic engineering, gene therapy and modern biotechnology. But decades later, his reputation was marred by racist and sexist comments that led to his isolation from the scientific world he once helped shape, according to Reuters. 

In his early career, Watson was known for both his brilliance and his brashness. His 1968 memoir The Double Helix offered a provocative and unvarnished look into how he and Crick made their groundbreaking discovery, describing scientists as "ambitious schemers" driven as much by rivalry as by curiosity.

Crick accused Watson of having "grossly invaded my privacy," while fellow researcher Maurice Wilkins criticised the book for creating "a distorted and unfavourable image of scientists." Both men, along with Watson, were later awarded the 1962 Nobel Prize in Medicine for their work on DNA.

Watson and Crick also faced criticism for relying on X-ray crystallography data gathered by Rosalind Franklin - whose crucial contribution was not properly credited at the time. As Watson himself admitted, scientific research is often torn between "the contradictory pulls of ambition and the sense of fair play."

"The tough Irishman" of molecular biology

Born in Chicago on 6 April 1928, Watson studied zoology at the University of Chicago and earned a PhD in genetics from Indiana University. At Cambridge University's Cavendish Laboratory, he met Crick and together they uncovered DNA's iconic "double helix" - a structure whose specific base pairing suggested, as they famously wrote in their 1953 paper, "a possible copying mechanism for the genetic material."

After their discovery, Watson joined Harvard University in 1956, where his blunt personality quickly made him a divisive figure. "The existing biology department felt that molecular biology was just a flash in the pan," Harvard biochemist Guido Guidotti recalled. "But when Watson arrived, he immediately told everyone ... that they were wasting their time and should retire."

That brashness, combined with his organisational drive, helped Watson build Cold Spring Harbor Laboratory (CSHL) into one of the world's leading molecular biology research centres. 

"The lab at the time was just a mosquito-infested backwater," biologist Mark Ptashne said. "Jim turned it into a vibrant, world-class institution."

The Human Genome Project and a public fall from grace

In 1990, Watson was chosen to lead the Human Genome Project - an ambitious plan to map the entire human genetic code. But when the National Institutes of Health moved to patent certain DNA sequences, Watson resigned in protest, arguing that genome data should remain freely available to the public.

Years later, he became the second person to have his complete genome sequenced, making it publicly accessible. He dismissed concerns about "genetic privacy" as exaggerated but refused to learn whether he carried a gene linked to Alzheimer's disease.

Watson's later career, however, was overshadowed by controversy. 

In 2007, he told The Times of London that he believed Africans were "not really ... the same as ours" in terms of intelligence - remarks that reignited long-debunked racist theories. The backlash was swift: he was suspended and later forced to retire from CSHL. Though he apologised, he repeated similar comments in a 2019 documentary, claiming racial differences in IQ were "genetic."

A conflicted legacy

Watson often embraced his provocateur persona. His 2007 memoir Avoid Boring People doubled down on his reputation as the field's rebel. Yet in a 2003 interview with Discover magazine, he said his greatest pride came not from discovering DNA but from his writing. "My heroes were never scientists," he said. 

"They were Graham Greene and Christopher Isherwood - you know, good writers."

Despite his reputation for sexism, some female scientists credited him for mentoring them. 

"I certainly couldn't have had a career in science without his support," said MIT biologist Nancy Hopkins. "Jim was hugely supportive of me and other women. It's an odd thing to understand."

James D Watson's story is one of scientific brilliance and human contradiction, a man whose discovery changed the world, and whose words later isolated him from it.

James Watson / DNA