I think this choice quote
the capacity of women across cultures to dissolve relationships that aren’t working has been much underestimated
perfectly illustrates my point in this post.
I think the nuclear family is a very recent concept, a couple hundred years, give or take. And it's not working out so well. People are rational creatures at heart, and divorce exists and is as popular as it is because it is helpful. That more women are choosing motherhood without marriage is because it is in their best interest to do so.
I could get all anthropological and start babbling about how all recent human evolution is lamarkian in nature and that the greatest of human leaps have been ones of cooperation like language and menopause rather than ones of competition like war, but everytime I get all philosophical it gets quiet around here.
So I'll just leave you with this. People are rational creatures. They will act in their own best interest, even when society at large says their actions are wrong. Women will seek to control their own fertility despite frothing mouthed protesters, gays and lesbians will push to be treated as equals despite frothing mouthed protesters, immigrants will cross dangerous borders looking for work despite frothing mouthed minutemen. Eventually, society will change it's view because those who act in their own best interest are the ones that carry society into the future.