(no subject)

[sciatrix]

"how has homosexual orientation evolved, given that, on average, homosexual individuals produce fewer children than do heterosexual individuals (this relative fitness relation between homosexuals and heterosexuals is considered an assumption for the purposes of this paper, given that the empirical evidence in the literature from Alfred Kinsey and others is weak)"

sir

do you hear yourself

do you hear yourself

I am not entirely sure if I can review this literature sober. The first thing I tackled was a piece purporting to be a review about proposed mechanisms for the evolution of female homosexuality; it spent three or four paragraphs explaining the possibility that bisexuality in women evolved for the purpose of attracting and interesting heterosexual men.

I cannot even.

Comments

[hebethen]

...please tell me this hails from at least a few decades ago?

[sciatrix]

2003! So not too recent, but then the same assumption still pervades the human evolution of homosexuality perspective (and much of the literature on nonhuman same-sex sexual behavior, which is what I was actually reading to inform at the time).

On the other hand, here's a line from Apostolou and Christensen, 2018, which kicked off a lot of (deserved) annoyance earlier this year in The evolution of same-sex attraction: Exploring women's willingness to have sex with other women in order to satisfy their partners:

About one in five women experience attractions toward other women (Calzo, Masyn, Austin, Jun, & Corliss, 2017; Dickson, Paul, & Herbison, 2003; LeVay, 2010; Savin-Williams, Joyner, & Rieger, 2012). Such attractions constitute an evolutionary puzzle because they appear to impair reproduction.

Or this quote from Burri, Spector and Rahman in 2015:

Homosexuality in both sexes appears persistent in spite of its reduced fitness differentials relative to heterosexuality in both Western samples and one non‐Western one 5, 6, 7, 8.

Incidentally, I have looked at those sources, and they date from 1978, 1981, 1995 and 2014 respectively--and the recent 2014 one is the Samoan paper (warning in it for pleeeenty of misgendering: I can't quite tell what the actual respectful form of address for the community under discussion is but I am very sure it ain't this). It's specifically studying fa’afafine Samoans who appear to identify on a transfeminine spectrum vis-a-vis a sample of what we would probably call cis straight men who are "exclusively gynephiliac."

The 1995 paper makes no comparison of relative rates of fecundity between its queer female samples and matched heterosexual controls; it doesn't even appear to have measured fecundity in any real way and used convenience sampling.

The oldest two sources, both by Bell and Weinberg, are books, not direct primary sources, and I can't be arsed to haul myself down to the PCL stacks to verify what they do and do not say about whether the queers actually incur any reproductive cost just now. But given the time at which they are writing... I'm skeptical.

[hebethen]

...yikes.

And I thought we got over the "only direct personal reproduction is a factor in selection pressure" thing.... idk how long ago, but long enough ago for me to have learned about it as a non-biologist. :|a

[sciatrix]

Oh, they went there first, actually; in fact, the paper I was initially quoting is a group selectionist argument for homosexuality being beneficial. He just hasn't gotten there yet in those few sentences.

No, the thing I have the grouchy irritation about is the assumption that homosexuality is inherently evolutionarily costly and so has to be explained. Humans have a whole lot of sex for a whole lot of reasons, some of which are not under any individual person's exact control (women especially here), and having sex with reproductively incompatible people does not preclude the possibility of at least occasionally having sex with compatible ones. So much of human survival rests on what happens after the sprog gets born that I just... don't see preferences as being all that evolutionarily visible, not when there are so many things potentially hindering human reproduction.

That being said, there are a lot of weird adaptationist arguments for why homosexuality out there, some of which have been more or less debunked and some which are under active study and academic fighting.