The fact that the pivotal contribution of one female chemist often goes unrecognized illustrates another important advance: The past 50 years have yielded a significant improvement in the climate for female scientists.
The discovery of DNA's helical structure was the culmination of an international effort that began in the 1880s, when scientists first identified a complex composite of compounds in the nucleus of the cell. The quest for knowledge about the molecule intensified during ensuing decades, especially when researchers learned it was the carrier of genetic information. But the problem of determining its precise structure seemed intractable, and a number of frustrated scientists dropped out of the race.
By the early 1950s, James Watson of Cambridge University was working with graduate student Frances Crick to deduce the structure using models, while researchers at London's King's College, Maurice Wilkins and Rosalind Franklin, were using X-ray diffraction methods to obtain data that might reveal DNA's architecture.
All accounts indicate that Franklin, a strong-minded, determined woman, encountered significant resistance to her participation in the project. Women chemists at that time generally were considered technical assistants. Franklin was a rare example of an independent female scientist and, moreover, apparently never hesitated to voice strong opinions or stand by her scientific hypotheses. Watson and Crick didn't hide their lack of enthusiasm about her involvement in the DNA structural studies. In his 1968 book, "The Double Helix," Watson notes, "The thought could not be avoided that the best place for a feminist is in another person's lab."
Franklin, however, persevered with her research. By most accounts, Watson and Crick were close to having the correct model, but aspects of it remained problematic. Independently, Franklin was generating the first X-ray photographs of the structure. When Wilkins showed Franklin's data to Watson and Crick - apparently without her consent or knowledge - they recognized an error in their model and the correct structure was immediately evident: a double helix of two intertwined strands.
>From this discovery, the scientists were able to offer a reasonable proposal for how genetic information could be copied. Watson and Crick published their ideas in the journal Nature in April 1953. Franklin supported their findings by writing an article for the same issue.
Watson, Crick and Wilkins received the Nobel Prize for the discovery in 1962. Franklin had died of ovarian cancer in 1958, at age 37, so she did not share in the award - a fact that has skewed recognition away from her contribution to the breakthrough.
In his book, Watson recognizes his team did not place enough value on Franklin's contribution, "realizing years too late the struggles that the intelligent woman faces to be accepted by a scientific world that often regards women as mere diversions to serious thinking."
Today, although still poorly represented in academia, women are accepted members of the scientific community. The improved climate has resulted in part from the efforts of modern female researchers, who have demonstrated that the ability to make high-impact scientific discoveries has nothing to do with gender.
However, more progress is needed to encourage talented women to pursue careers in science. In the United States, for example, about 40 percent of science majors are women, but the gender gap grows in Ph.D. programs and explodes for tenure-track academic positions. Additionally, women trained as scientists are still less likely than men to remain in the field as their careers progress.
This problem must be addressed at all levels of the educational process. Early on, we must help young girls to realize their aptitude for math and science and give them confidence in their quantitative abilities. In addition, we must intensify recruitment of talented women into the field - promoting science as a career beyond a course of study - and we must support their efforts to advance.
We also must encourage young female scientists to cultivate tenacity. Franklin was not deterred by challenges of science or gender bias. Through strong will and a refusal to be marginalized, she produced essential data that helped to change the face of modern chemistry.
Franklin's perseverance should be acknowledged at this anniversary. It also should serve to inspire women contemplating or beginning careers in the sciences today.
Shana O. Kelley is assistant professor of chemistry and a DNA researcher at Boston College.