Where The Males Have (Little) Vaginas And The Females Have (Big) Penises, Ctd

We learn something new from readers every day:

I enjoyed that link on the gynosome, but I think that your coverage of sexual orientation and biology focusing on things like 29saw_drawing-blog480bug penises miss issues about sexual orientation that genuinely fascinate biologists. The concept of “natural law” doesn’t really carry much weight with actual biologists, and it’s not all that surprising that there is an insect in which the female has a penis.

There are hundreds of species with these sorts of reproductive role reversals, including males who incubate eggs internally or even in their mouths, and in which female parental investment is limited. At this point, it’s almost trivial to point out that same-sex behavior and even same-sex parenting is common in nature, or that every possible variation on genitalia occurs somewhere in nature. Even in mammals, there are females with “penises.” Female hyenas have pseudo-penises bigger than those owned by males, and they swing their dicks with more élan and pride than the males do!

This is all entertaining, but it misses the deeper and more interesting question evolutionary biologists ask about homosexuality:

“Why does a trait that appears to reduce reproductive fitness persist?” There’s no moralizing about right or wrong in this question, just curiosity about how same-sex sexual attraction makes sense from the standpoint of natural selection, when it appears to lead to reduced reproduction on the part of those who have this trait. All of the unusual traits discussed above really do result in increased reproductive fitness. But same-sex sexual attraction itself? Now that’s a different and more interesting issue than the gender role differences and odd anatomy described above.

Biological speculation on this issue is based on a few assumptions. First, there is a strong indication that being gay is an inherent biological trait mediated by genes rather than a cultural variable or something that is socially constructed, given its apparent occurrence in roughly the same percentage across human populations at all times.

Second, it must not be maladaptive or it would not persist. I’d like to refer you to an older Scientific American blog post by a gay evolutionary biologist that outlines some of the thinking on this issue. I do hope you get a chance to read it, because one of my very few complaints about the Dish is that I wish you discussed science with more of the subtlety and depth of understanding with which you discuss faith.

(Image of a not-male hyena by Christine Drea)