This article by The New Agenda’s Nancy Hopkins is published at MORE.com and also featured in the Cheat Sheet at The Daily Beast.

Hopkins, an MIT professor, walked out when the president of Harvard implied that women scientists were innately less talented than male ones. Now, the Nobel Prizes give her the last laugh.

It’s been a spectacular week for women in science, and a bad week for “the Larry Summers hypothesis.” In 2005, while president of Harvard, he suggested that women are inherently worse than men at math, science and engineering, particularly at the highest levels. This week three women won Nobel prizes in science: two in medicine and one in chemistry. That achievement should put the nail in the coffin of the question Summers raised: Can many women really be great scientists?

When I was a graduate student in biology at Harvard 40 years ago, my colleagues used to sit around discussing whether girls were capable of being great scientists. Could a woman really win a Nobel Prize in molecular biology? Men I knew wondered if women’s brains were so different from men’s that they couldn’t make the creative breakthroughs that lead to the greatest discoveries. That’s what I wondered too. Sure, there was Madame Curie–but there were too few Madame Curies to convince us she was anything but an exception.

It turns out that back then, in the dark ages for women in science, we were asking the wrong question. Instead of asking if women’s brains were inferior, we asked why there were so few women at the major research universities and laboratories that breed future Nobel laureates.

In the late 1960s there were essentially no women on the science faculties of places like Harvard, Cal Tech and MIT (where I now work as a professor of molecular biology). Things began to change dramatically in the early 1970s, thanks to affirmative action measures taken under Richard Nixon. Those included the “Shultz regs” (George Shultz was Nixon’s Secretary of Labor), which required universities to hire women onto their faculties or risk losing their federal funding. The Nobel prizes in medicine this week are the end result of those laws. Nobelist Elizabeth Blackburn joined the Berkeley faculty in 1978 and Nobelist Carol Greider was her star graduate student. (The third new laureate is Ada Yonath, an Israeli.)

Until about 10 years ago, women still comprised only five percent of the science faculty at Harvard and eight percent at MIT, with similar numbers at other high-powered research universities. (Today 17 percent of the MIT science faculty are women, as a result of specific efforts by the MIT administration in collaboration with senior women faculty.) But even those paltry numbers from 10 years ago have been enough to start yielding female Nobelists. In fact, if we assume that female faculty win these prizes at the same rate as male faculty, then only in the past couple of years have there been enough women employed at MIT to begin producing Nobel laureates.

Meanwhile, women faculty at MIT are now elected to the National Academy of Sciences at the same rate as men, and they have finally begun to win some of the most prestigious science awards. For example, yesterday a woman from MIT–the great chemist JoAnne Stubbe–received the National Medal of Science from President Obama, in part for developing a cancer-treating drug now in clinical trials. She has also worked to make science more welcoming for the young women who will come after her. Her accomplishments are off the charts.

Every time a female scientist wins one of these major awards, it is very emotional for me, reducing me to tears. Most are tears of joy at seeing these amazing pioneers recognized for their achievements after the decades-long struggle for women’s equality in science. But I am also sad, thinking of all the great discoveries that were lost when half the population was kept out.

My emotions may even include a trace of I-told-you-so. It’s shocking that as recently as 2005 Larry Summers could propose that women’s genetic inferiority might explain their small numbers at the pinnacle of scientific achievement. I walked out in protest. You’d expect Harvard to know better!

Maybe 2009 will be remembered as a watershed for women in science. At the very least it should mark the end of the nonsensical, outdated and damaging idea that women lack the interest or genetic ability to do great math and science.

Nancy Hopkins is professor of molecular biology at MIT and a founding member of The New Agenda.