Watson and Crick published their proposed structure for DNA in April 1953 in the ​​journal Nature.³ In the same issue, Wilkins, Franklin, Gosling, and their colleagues presented the ​​evidence they’d collected, which supported Watson and Crick’s two-chain helix ​​hypothesis.⁴ In this way, the evidence and hypothesis relating to the structure of DNA entered the ​​scientific literature and became available for other researchers to build on.

But not everything that went into these papers came from freely available sources. Scientists often use others’ ​​data and ideas, but they are expected to give credit to their sources. This allows ​​science to grow by building on existing ideas, while rewarding individual scientists for their contributions. Crick and Watson’s paper did give credit for much of the evidence they’d collected during their investigation of the structure of DNA. However, data inspiring some of their key insights came from Franklin’s 1952 report to the Medical Research Council — which was supposed to be confidential information. Franklin never gave Watson and Crick permission to use that work, and in their paper — the scientific record of this discovery — they do not credit Franklin for supplying this evidence or for image B 51, which was so critical to their discovery. Retrospectively, both Crick and Watson acknowledged their debt. According to Crick, “all the really relevant ​​experimental work on the X-ray diffraction patterns of DNA” came from Franklin’s lab, and Watson later claimed that their discovery would not have been possible without the data collected by Franklin.

The failure to give full credit to important evidence is considered a serious infringement of scientific ethics. Crick and Watson have both had highly successful scientific careers, but the issue of whether or not they acted fairly has continued to follow them. In interviews and public appearances, they were — and are — frequently questioned about their choices and about Franklin’s role in their most famous discovery, and have had to endure the scrutiny and judgment of the scientific community.

It’s also worth noting that Franklin was a pioneer in terms of women’s presence in the sciences. At the time Franklin was working on DNA, less than five percent of Ph.D.s in the physical sciences were awarded to women.⁵ Franklin never reported specific examples of discrimination (aside from not being allowed to eat with her male colleagues in the senior common room), but she did worry that her work might not be taken seriously because of her gender. Though we can never know for sure, it’s certainly possible that the discovery of DNA’s structure — and the credit given for it — would have played out differently, had the social environment for women scientists been fairer.