What we learn from looking at nature is the amazing diversity in gender roles, even outright switching of ‘typical’ roles in some species. I actually don't see any "rule" that gender has to express in any particular way across species. There isn't always sexual reproduction -- many species have asexual reproduction. In humans, there are gender differences at the level of gametes and plumbing and hormones and such, but there are vast areas of social interaction where no gender roles are necessary and would be harmful to the development of the individual, and would deprive society of the gifts of the individual. What are you suggesting, that there is a rule that women should be confined to certain activities, and this is the will of 'nature's god' -- with exceptions? I think our identity is that we are 'made in the image of God,' and all of our Being is rooted in Mystery, not in some weird sexist interpretation of biology, with sexist rules.