I'll briefly summarize some of the issues we've discussed and the research behind them.
All qualifications being equal on paper, female college graduates (intending to go on to grad school in science) are perceived to be less competent than identical male college grads (Science faculty's subtle gender biases favor male students). Many excellent bloggers have written extensively about this new research (here, here, and here for starters). It is important to note that both men and women who were evaluating qualifications rated men more competent than identical women.
A similar gender bias exists in single-blind peer review (Double-blind review favours increased representation of female authors). This suggests that double-blind peer review reduces unintentional gender bias that subtly discriminates against work by female authors.
In psychology, identical cv's with male or female names found lower rates of hire (at the assistant professor level) and starting salaries for the female name (The impact of gender on the review of the curricula vitae of job applicants and tenure candidates: A national empirical study).
The emerging story from experimentation is that based solely on their perceived gender, women are perceived to be less competent in science, less likely to get papers published, less likely to be hired, and offered lower starting salaries (pre- and post-PhD). These are issues that affect women regardless of their partnership or parenthood status.
Additionally, many researchers have gathered information from scientists at various career stages about other factors that influence metrics of success (salary, grants, publications, etc.) such as work-life balance and parenthood.
A survey of academics from various fields at different types of institutions from across the U.S. found that among partnered academics, women tend to have partners who work more hours than men (Balancing Parenthood and Academia: Work/Family Stress as Influenced by Gender and Tenure Status). Women are much more likely to have spouse who is employed more than 40 hours per week. They also found that women tend to do a larger share of childcare/housework, even when their spouse is also employed full-time. Very similar results were found in a survey of tropical ecologists by the Organization for Tropical Studies (Dramatic Improvements and Persistent Challenges for Women Ecologists). A good overview on this topic is The family life of academics: gendered priorities and institutional constraints.
Considering the present challenges, what ideas do you have for leveling the playing field for women, particularly in science and academia? What can be done to better accommodate caregiving responsibilities? Do you know of any institutions (e.g. universities/granting agencies) with exemplary policies?
I've heard suggestions (some of which are already enacted to various degrees) such as wider adoption of double-blind peer review (as mentioned above), allowing child care expenses in grant budgets, improving parental leave options (maternal AND paternal), and adjusting the tenure clock. I have to admit that I know little about tenure clock policies, so I'd love to hear suggestions for readings on that topic.
I worry sometimes that discussion of women's issues focus heavily on parenthood, which can be narrow, presumptive, and alienating for women who cannot or choose not to have children. I'd also love to hear comments from readers outside the U.S. on the pros and cons of their policies affecting women in science in their countries, since my perspective is very U.S.-centric.
I'm purposely not being too specific in terms of solutions other people have suggested, but a 2009 report, Staying Competitive: Patching America’s Leaky Pipeline in the Sciences, offers many suggestions (especially regarding issues related to parenthood).
Note: I believe that all of the articles to which I linked can be found for free online, but not necessarily via the links I provided. If you can't find any of these, feel free to email me.