The world’s population expoded after 1900, straining resources and causing many species of plants and animals to go extinct. The population growth can’t be sustained, especially with western standards of living. Thankfully in some societies (ones where you don’t have to breed your own fifedom to be king to feel important) it’s becoming ok to have only a couple of kids.
I don’t know - flies get horny, I get horny. 
You’d think that attraction to the opposite sex would be a pretty basic gene or set of genes, and not something that gets reinvented with every species. That doesn’t mean I think the study proves anything - Fiveyearlurker’s criticism sounds pretty reasonable to me.
You could think about how as noted earlier, we share 75% of or genetic make up with pumpkins. Plants, insects and reptiles all have ample examples of hermaphrodity (word?), sex switching and varying levels of asexuality. It’s already pretty obvious in humans that what makes you horny doesn’t direct that horniness (eg testosterone given to gay men makes them just hornier for men)
Yeah, but evolution is constantly allowing things to be replaced by other things - it’s not a given that the same general type of outward behaviour is the result of anything at all similar genetically, at least not in such distantly related species. There would be quite a strong case for it being related mechanisms in, say, all mammals, or maybe all vertebrates (although I start to wonder there).
However, every generation in an evolutionary tree must experience some mechanism that makes them breed, so there’s a stronger case for the preservation of whatever works than there would be for other features - perhaps physical things such as eyes or legs, which get reinvented from scratch every so often.
I was thinking about this thread, and something kind of came to me thinking about nameless’ cited studies. The fact that a genetic propensity to larger families coincides with a propensity to homosexuality doesn’t actually show that homosexuality isn’t harmful to general population growth,
As the apparently more expert John Mace agreed, it’s certainly plausible that genetic references that cause men to be gay could possibly also cause more family/child/build the village type feelings in lesser manifestations. That doesn’t mean that being gay doesn’t negatively affect the birth rate. If we could give an injection to all those big family gay guys that turned them straight,you think a few of them might have some kids - if only by ignorant accident? Do you really think the rest of the extended family would have less kids to compensate?
I know the population’s gone through the roof, but that’s not because people are having orders of magnitude more children - it’s because far more of them are surviving. And in my naivetë I thought I’d made that very point already.
Ouch, my feelings.
That’s silly. You’ve added an experimental manipulation and are now measuring something entirely different.
Let’s say you claim that early onset Alzheimer’s (a partially genetic disorder) kills people, reducing family size. I have a cure for Alzheimer’s. I now say, “Nuh uh, it doesn’t reduce family size, because I can cure it, and those people I cured might have more kids, and now the family’s bigger.”
The reality of the situation is, those genes that cause early onset Alzheimer’s are still there. In the absence of my intervention, Alzheimer’s still kills people. The only difference is that you’ve manipulated the population to change the outcome. What you’re measuring isn’t whether naturally occurring homosexuality is correlated with family size; what you’re measuring (or should be measuring, anyway) is whether or not you can reverse homosexuality’s negative effects on procreation in an experimentally manipulated individual.
Meant to add this to the discussion of early-onset Alzheimer’s–
Furthermore, if those genes that cause Alzheimer’s have some positive effects on viability (say by heterozygote advantage or some other mechanism), those will remain in place in individuals who aren’t treated for Alzheimer’s disease.
A population of 100 million will have about two orders of magnitude more children than a population of 1 million (“about” because minor deviation as a result of family size variation can shift the ratio slightly). That’s basic arithmetic.
I meant more expert than myself. Maybe he’s more expert than you, as well.
No it’s not silly and I don’t see what new thing I’m measuring. As far as I know, I’m just giving another idea of why gays may be more likely to have larger extended families. I don’t think Alzheimer’s, or any fatal disease for that matter, is a good example to look at. We’re talking about traits and behaviours that can manifest in a spectrum. It is entirely un-silly to recognize that expression of certain traits may be beneficial up to a point. Imagine a set of genes controlled penis size and in a particular tribe of naked people that was a useful umm tool in courtship displays. At a certain point a penis gets to be too large for a proper erection, leaving him effectively impotent.
How is this any different from the argument that because species existing without higher brain functions being capable of sexual discrimination proves that sexual orientation is not a choice?
It doesn’t matter why homosexuality exists or occurs - it is by logical necessity of the same nature as heterosexuality and therefore deserves equal treatment. Any argument you can make against or for one you automatically can make for the other (aside from perhaps arbitrary human codes such as religious and legal).
Undoubtedly. I’m an expert in very few things 
Maybe I’m misunderstanding you. I have already done that once in this thread. I have asserted–
(1) Some studies show that families with gay members exhibit higher female fecundity (specifically in female maternal relatives of the gay individual).
(2) One possible explanation for this is that genes associated with homosexuality confer some increased reproductive output in females.
Your counterargument, as it appears to me, is–
(1) If we reversed the sexual orientation of the gay men, they might have kids, and the family would be even larger.
(2) Therefore, familial size is still negatively impacted by homosexuality.
To which I would respond–
But in this experiment, you’re not measuring the effect of homosexuality on familial fecundity. You’re measuring the effect of a homosexual to heterosexual orientation therapy on isolated individuals, then adding the resulting fecundity difference to the family as a whole. If there are genetic factors that both promote homosexuality and high fecundity, you’re not eliminating the effects of these factors in non-homosexual family members. Now if you did gene silencing in the entire family against whatever target genes you thought were involved–that would be definitive.
Or am I horribly misunderstanding you?
I agree. That’s an evolutionary argument for the persistence of same-sex behavior–genes that promote same-sex behavior also promote high fecundity somehow. This is compatible with the research I cited.
As a Primatologist, I am biased, but I think the best way to learn about homosexuality and the implications thereof is to look at our primate relatives instead of non-primates, particularly the great apes, although parallels can be found when researching any primate species. Anyway, I am currently writing a term paper on the functions of female-female sexual behavior in two separate species.
Anyway, true homosexuality is rare in primate species. I was able to find some references to such individuals, but it seems far more likely that most humans (like most other primates) could be properly called bisexual. This bisexuality allows for homosexual acts which can confer many evolutionary advantages to the individuals and the species as a whole. For example, among Japanese macaques, there is a lot of evidence that female-female courtships and sex is a by-product of natural selection that selects for higher reproduction rates in most of its female members. In comparison, female-female sexual behavior appears to serve more of a social function in bonobos, where females use homosexual sex to do many things including control males.
Any “gay gene” study immediately makes me suspicious and probably has no hold on human behavior. All the evidence that I’ve seen as far as homosexuality goes in primates (and this is my area of study so I’ve read a lot) suggests that there is no single gene that controls sexual behavior. Most of the evidence suggests that it is polymorphic trait.
No, I don’t think you’re horribly misunderstanding me.
Yes, that would be “definitive” if I was running a test. But if I took that as a given and therefore accepting that there’s a true genetic link between occurrences of gay men and high baby volume producing women in a family, then if I wanted to eliminate homosexuality as a population growth hindrance, I wouldn’t do a general population treatment to get rid of it. I would only want spot treatments so that only gay family members would get it, so as to still reap the benefits of the high fecundity females. If the treatment was perfect it would not alter the formerly gay person’s ability to pass the fecundity-helping genes. But even if it didn’t, it’s a simple matter of logic and fact that a straight man is more likely to produce children than a gay man - he was kind of a dead end for the genes anyway. I don’t see how spot on treatments could fail to produce more children. It seems to me that in that way I could keep the benefits, indicated by your cited surveys, intact.
Though to be honest, I was thinking a little more generally, in that the genes that may influence you to be gay might make you more likely to be home/family building type of guy in lesser expressions, in addition to how it might spell out in the female fertility arena.
If you think I need schooling in basic arithmetic, get thee to a phrenologist. If you want to argue that we’re having orders of magnitude more children, please specify whether or not that is per head of population or absolute, and then we won’t get into these little misunderstandings. kthxbye!
Man, what does it matter what the effect of homosexuality on family size is? Are we in some kind of crisis mode where a person is doing the world a disservice by not having more children? It hardly seems that way. If it ever got to the point that humanity felt a dire need to make a special push to perpetuate the species, presumably gay people would feel that fervor as much as other people, and start having babies pretty much just as easily as they could if they were straight. Sure, if the world were enshrouded in magic gas turning 90% of llamas gays, then the world population of llamas might crash. But humans are a bit smarter than llamas, are capable of understanding the mechanism of producing children, and if they want to do so, they don’t have to be “tricked” into it by physical desire for heterosexual sex. If it should turn out that every single person born in the century ends up gay, it would be bizarre, but there would be nothing “bad” or “harmful” about it, certainly not any danger to humanity. Of all the ridiculous things to talk about…
Well, I was going to mention earlier, Malacandra, that an estimate of historic birth rates would have also been useful, depending on exactly what your guy’s points were regarding that statistic. I don’t think there’s any need for anyone to get huffy, slight obnoxiousnesses aside, I think it might be a simple misunderstanding.
eta: Indistinguishable, we aren’t the Parliament here; just shooting the geneto-political shit,
I believe birth rate per capita would be the best stat to examine concerning the question of whether we’re in any danger of breeding below replacement rate, but if someone wants to make a case for total number of children born and explain how that addresses the question at all, he can get right to it. Still, what with not having any axe to grind here, I’m not planning on being perturbed for very long.
Oh, but if it was a cultural effect, ie knowing they had a gay/permanent bachelor relative caused other family members to have more kids, then my social engineering would perhaps fail.
eta: Fair enough, Malacandra. Let’s see what Steve MB says.