Hi,
First the short intro. I am a biologist and I have been editing wikipedia since January 2006. Currently, I am an admin and bit more active than a long time.
I am not at all surprised about the gender gap. I think the setup of wikipedia from the beginning fitted far better with the way man are used to operate than how woman are used to operate. Vandal fighting, edit wars, etc, who wants to do that? Maybe I am wrong, but there is a something we can use, and that is data mining. Just as the gender gap was discovered. Basically, what is needed is an analysis of the data and if there is a difference in the editing pattern of men and women. We can than use those results to actually get a better idea why women are absent.
I make a prediction. Nothing is going to change, regardless of what we find and discover, unless we find a way to change the governing system (the community rules). But as the current system is dominated by men, we have to convince them to change the rules. Good luck with that.
Kim