Women have a different intelligense distribution curve. While the average is the same, most women are found near the average, while men have much wider distribution. So the smartest and stupidest people are dominated by males.
Another reason you find few women among known smart people is because few women have been allowed to study and explore through history. With a few exceptions like Marie Cürie, there have essentially been none before maybe the last 50 years. Also, given how long it takes to go through school, do research and make yourself a name in the world, the top scientist crew's gender distribution reflect the society of a few decades ago rather than today's.