Freaks of nature! How dare they defy and reverse traditional gender roles? Nurturing is a female trait! Raising children is a mom's job! Males are to make the money and feed their families! What business do they have changing what has been done since the dawn of time and what is clearly the standard in nature?!
...no, I'm not talking about people who are gay or single parents. I'm talking about... nature. Fact: throughout nature, species have adapted to varying conditions by switching things up a bit. Of course, this was sparked by a National Geographic web article published for Father's Day and reinforced by my knowledge of the animal world. What doesn't work for certain species proves to work for others, given environmental, biological, or ecological circumstances or niches. Life adapts.
Of course, I'm not saying we should eat our young when we can't feed them, or carry our babies by the backs of their necks, or force women to have sex, or bite men's heads off after they've fulfilled their sperm-donating role. And as far as I know, few head-wife polygamous women are capable, when their husband dies, of becoming a man and assuming his role, as certain fish are. I mean, apparently "nature" doesn't have religious beliefs or morals to prevent it from adapting in certain ways, and not all species carry the same genetic programming.
Different species seem to have different instinctive tendencies as a whole, so if you want to argue that human men and women are programmed differently, you can debate that. I think that though there are hormonal and chemical differences between male and female which surely influence 'natural' tendencies, whether or not those can be overridden by rationale or effort, most gender "roles" and family archetypes are socially programmed and culturally reinforced, often heavily influenced by religious beliefs and values rather than science or "what works". I'm just sayin' the "unnatural" argument against nontraditional gender roles or families based on what is observed in the rest of nature is weak sauce. Psh.
And I wanted an excuse to post lots of pics of cute animals. Aaawww, precious...