# Evolution and the prevalence of homosexuality **URL:** \ **Category:** Factual Questions\ **Created:** [November 12, 2014, 4:05pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458 "2014-11-12T16:05:35Z")\ **Posts on this page:** 15\ **Page:** 3
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [November 13, 2014, 11:39am UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/41 "2014-11-13T11:39:14Z")
> [@Urbanredneck](#): > > Modern San Fransisco, Paul Lynn-Ellen Degeneres homosexuality is different from the concept of plain sexual attraction to ones own gender. In the past people with those attractions just fell into life and societys norms and had families and children while just seeing their own gender on the side. > > Its only in modern times where they can live openly and all. Homosexuality is a 19th century western construct. In modern non Western socities, you have people who openly partake in same sex relationship s but will deny they are homosexuals till they are blue in the face. Which is quite challenging in identifying historic gay people. Both Alexander and Edward II were gay under modern definitions but both married and had children as well as bastards from politically unimportant heterosexual affairs. And of course situational sexualiy is well attested. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [November 13, 2014, 1:18pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/42 "2014-11-13T13:18:11Z")
> [@mr.jp](#): > > Recognize members of the opposite sex, and desire to do sex with them. Seems way less complex than say, language capability, or the liver. How do you activate the desire to have sex? Please be specific and mention all involved neurons and hormones. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 13, 2014, 1:38pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/43 "2014-11-13T13:38:12Z")
> [@Essured](#): > > Do you have any cite for this, or is it just a WAG? > I find it _very_ strange to assume that female choice would have no evoutionary impact. Why would it be one-sided? It would be extremely interesting if that was the case. It’s not like forcible rape is the most common method of reproduction in humans, or most of the primates (AFAIK). > Birds for example - don’t many species have the male competing via dance, plumage & nest-building with the female selecting her mate based on what she sees? I’m sure there are similar examples in the primate world, if only because the primate world covers vast differences. > > So yeah, just wondering if there are actual scientific / evolutionary theories that suggest female mate selection has no impact on reproductive outcome? Just a WAG. The true model for the process of human evolution (read Jared Diamond’s _The World Until Yesterday_) would be the small village or clan, a collection of extended families. To what extent would such a social structure tolerate single persons of either sex? To what extent are they capable of such support? What are the odds two gay persons of the same gender and roughly same age would occur in a group of 20 to 100 individuals? I was thinking of the native North American model (which is shown in IIRC “A Man Called Horse” or “Little Big Man”) but that was the gay male role. There was no apparent corresponding female role. Again just a WAG, but unlike modern society, there was no job and money to go out and buy Doc Martens; there were tasks to do to survive - there was hunting (male role) there was food preparation, gathering of plants, making clothing, etc. Society usually did not have a role for someone who did not want to pair up, and there was less incentive for the extended family to support someone who didn’t “play the game” so to speak. (And in one of the movies I mention above, there is also the scene where when the old woman’s husband dies, the rest of the tribe takes the couple’s possessions and pushes her out in the cold to die.) Of course, male domination goes a long way too - we see plenty of societies where women basically have little to no say in their marriage arrangements. * * * When someone suggests to me that homosexuality is a “choice” (WTF?) I point out that nobody told me what I wanted or liked, that my deep heterosexual desires were in no way taught. I grew up before sexual material was widely available to the curious youngster, and did not get a lot of exposure to such - yet I know what I like. To me, this seems to show that such desires are very instinctual, on the level of the instinctive behaviour programmed into many other species. Meanwhile, we do have the instinctive recognition of other humans (and other animals) in non-sexual ways; we can tell pretty or handsome from not, and most people agree what constitutes “good-looking”. We can tell young from old, we can tell “cute” and “repulsive” deep in our gut, and so on. (A lot of women especially, I’ve seen, have a very strong response to snakes… and nothing to do with bible stories) To me, this suggests deep instinctive programming, not learned responses. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [November 13, 2014, 1:40pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/44 "2014-11-13T13:40:17Z")
> [@mr.jp](#): > > Recognize members of the opposite sex, and desire to do sex with them. Seems way less complex than say, language capability, or the liver. Does anyone on earth have the desire to have sex with _all members of the opposite sex_? ---
**Author:** ![Mdcastle](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mdcastle](https://boards.straightdope.com/u/Mdcastle)\ **Post date:** [November 13, 2014, 2:43pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/45 "2014-11-13T14:43:17Z")
> [@md2000](#): > > Evolution works with what it’s got. (For what it matters, I know a pair of identical twins, one is gay and one is heterosexual and has 4 children…) > > My theory - there’s a series of “recognizers” our brains are preprogrammed to recognize things - healthy, young, old, cute (as in babies and puppies are “cute” attractive), repulsive, etc. This is how evolution has shaped our brains and the way they work. In order to construct he complex mechanism of our brains, things have to connect “just right”. If during gestation the program (for lack of a better word) for what turns someone on accidentally develops or gets connected to the program designed for the other sex, then that’s a price to be paid for having a flexible system that allows a strong sex drive in the first place. > > Using this hypothesis, then homosexuality or other diversions of sex drive are simply a side effect of the path evolution has chosen. To correct this would require backing up to a completely different method and creating a different method of connecting urges to sex drive. > > So Mother Nature will tolerate a certain amount of “error” in order to get the result that works for reproduction, let’s say 90% of the time. You’re assuming there’s a gene that says straight/gay when likely it’s more like there’s a gene that says something similar to “make a toe, another toe, etc. up to 5 toes” and if it accidentally makes 4 or 6, well, that’s the result of the mechanism involved having occasional misconnects. The gene(s) may say something like “I’m detecting male development, find the ‘I like females’ program among many and hook it into this part of the brain”. > > Also, based on human nature, female sexual urges probably didn’t figure much into their ultimate reproductive outcome, knowing what we do of typical male behaviour over the course of history. So there wouldn’t be any selection there anyway… So is this where pedophilia and fetishes come from? Connections that got miswired? ---
**Author:** ![mr.jp](https://avatars.discourse-cdn.com/v4/letter/m/48db29/32.png) [@mr.jp](https://boards.straightdope.com/u/mr.jp)\ **Post date:** [November 13, 2014, 2:59pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/46 "2014-11-13T14:59:07Z")
> [@naita](#): > > How do you activate the desire to have sex? Please be specific and mention all involved neurons and hormones. If you don’t think coding this desire seems like a more simple task than coding a liver, that’s fine with me. It’s just a thought. Insects and such seem to be able to do it, while being significantly less complex than us. ---
**Author:** ![mr.jp](https://avatars.discourse-cdn.com/v4/letter/m/48db29/32.png) [@mr.jp](https://boards.straightdope.com/u/mr.jp)\ **Post date:** [November 13, 2014, 3:10pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/47 "2014-11-13T15:10:49Z")
> [@jtgain](#): > > I vote for the in utereo suggestions stated upthread. That makes the most sense. The thing about this is that the in utero conditions are also heritable, just on the mother. So we then have to explain why genes are inherited that cause a specific environment in the uterus. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [November 13, 2014, 3:21pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/48 "2014-11-13T15:21:27Z")
> [@mr.jp](#): > > The thing about this is that the in utero conditions are also heritable, just on the mother. So we then have to explain why genes are inherited that cause a specific environment in the uterus. Why would genes be the only reason something is heritable? That’s a big leap. That ignores epigenetics entirely, for starters. ETA: Seems like this is a point that’s been made already in this thread - reducing all heritability strictly to genetics is questionable. Actually, we know it’s not true. There are other “nature” elements beyond strict genetics that don’t cross over into “nurture” territory. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [November 13, 2014, 3:31pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/49 "2014-11-13T15:31:16Z")
In “genetic/evolutionary” discussions, what kind of conclusions can be made about the ultimate steady-state percentage of putative genetic material among the population given that a lesser percentage express it phenotypically? ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 13, 2014, 6:55pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/50 "2014-11-13T18:55:55Z")
> [@Mdcastle](#): > > So is this where pedophilia and fetishes come from? Connections that got miswired? It’s a possibility. I guess the question is, to what extent are these traits inborn like straight or gay? To what extent are they “learned” behaviour from being abused themselves? The biggest sex organ in the human body is the brain. It’s complex enough that it’s very difficult to figure out what is going on at any time. There are plenty of non-sexual quirks and obsessions the human brain is capable of too. At this point it’s important to separate sexual pleasure from social dominance. There’s the old saw, for example, that rape is more about power and dominance. To some extent, he same would likely apply to S&M and pedophilia (where pedophilia activity is a learned experience, the perpetrators acting out after experiencing abuse themselves). It’s possible, though, that perhaps some forms of pedophilia are miswiring of the brain. S&M, similarly, seems to be attaching pain to sexual activity (either giving or receiving). I’ve never made a study of what causes this sort of behaviour. I’m going to make the guess, however, that more superficial obsessions - liking red lingerie, for example - is learned behaviour while more basic desires - liking large breasts, perhaps - is more instinctive. But, if certain results are accidents of fetal development, then it’s entirely likely that factors like birth order, etc. can influence whether these accidents happen. My guess would explain why the “problem” happens. Evolution has taken programmed instinctual behaviour and adapted it to work in a very pliable, flexible brain. To correct this would require a radical redesign of the brain. maybe when we’re all forgotten and dust, intelligent cockroaches will evolve that don’t have gay offspring. So far, our brain works “good enough” and that’s all Nature aims for. ---
**Author:** ![mr.jp](https://avatars.discourse-cdn.com/v4/letter/m/48db29/32.png) [@mr.jp](https://boards.straightdope.com/u/mr.jp)\ **Post date:** [November 13, 2014, 7:18pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/51 "2014-11-13T19:18:39Z")
> [@Great\_Antibob](#): > > Why would genes be the only reason something is heritable? That’s a big leap. > > That ignores epigenetics entirely, for starters. > > ETA: Seems like this is a point that’s been made already in this thread - reducing all heritability strictly to genetics is questionable. Actually, we know it’s not true. There are other “nature” elements beyond strict genetics that don’t cross over into “nurture” territory. Not the only reason, but they are an important factor, and this is mainstream genetics. For the purposes of this thread, let’s assume that evolution can act on heritable traits. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [November 13, 2014, 7:41pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/52 "2014-11-13T19:41:35Z")
> [@mr.jp](#): > > Not the only reason, but they are an important factor, and this is mainstream genetics. For the purposes of this thread, let’s assume that evolution can act on heritable traits. Ok, then that leaves the door open that there are not necessarily specific genes that create those certain conditions in the uterus or that such genes are not common across most, if not all, humans. That there’s an epigenetic explanation for those uterus conditions which are correlated with homosexuality. Even so, does it matter? Humans are pretty darned successful at breeding. Rather than looking for a reason why homosexuality is selected _for_, there’s no reason, at current rates of expression, any biologically driven (whether purely genetic, epigenetic, or whatever) conditions favoring homosexuality should be selected _against_. That may be different if it was expressed in 95% of the population, but it’s not. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [November 13, 2014, 8:30pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/53 "2014-11-13T20:30:23Z")
> [@Great\_Antibob](#): > > That may be different if it was expressed in 95% of the population, but it’s not. Heck, even if it was expressed in 95% of the population, all you’d need is for enough women to look for enough “sperm donors” for the number of children they want. You couldn’t have a low-tech monogamous solution… but how many humans have ever been truly monogamous anyway? Given all the complex mating behaviors in nature, this would be a pretty simple one to solve. It’s not like we’re one of those solitary species that has to travel a thousand miles to meet at a particular full moon on a particular beach… and yet even those guys manage to reproduce. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [November 14, 2014, 4:01am UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/54 "2014-11-14T04:01:48Z")
> [@Great\_Antibob](#): > > That may be different if it was expressed in 95% of the population, but it’s not. Why stop there? 100% of strong heterosexuals could die out and the human race would carry on just fine, and better dressed. ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 14, 2014, 3:15pm UTC](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458/55 "2014-11-14T15:15:55Z")
> [@dracoi](#): > > Given all the complex mating behaviors in nature, this would be a pretty simple one to solve. It’s not like we’re one of those solitary species that has to travel a thousand miles to meet at a particular full moon on a particular beach… and yet even those guys manage to reproduce. That last line reminded me indirectly that in many species, most “guys” (males) do \*not \*manage to reproduce. (Most “gals” do.) Since the sustainability of a population depends mostly on female fertility, this might hint that it’s not that crucial for Mother Nature to prevent male homosexuality. (Note too that most surveys tend to find lesbianism less common than male homosexuality.) [Previous page](https://boards.straightdope.com/t/evolution-and-the-prevalence-of-homosexuality/704458.md?page=2)