Homosexuality can be turned on and off in Fruit flies

[Acid Lamp]

Neat. Link (http://www.livescience.com/animals/071209-fly-genes.html)

Turns out that in fruit flies at least, it is linked to perception of scents and some other factors. Another nail in the coffin of the old homosexuality is a learned behaviour argument. :cool:

[Miller]

If you turn it off, are they still fruit flies?

[Menocchio]

When I was in grad school, a student submitted a mock proposal on the subject. It was interesting to see what happened when such a socially and politically charged subject is discussed with dispassionate scientific jargon.

For example, when you restore wild-type function to a mutant, you're said to "rescue" the phenotype. I have to admit, I raised an eyebrow when the student described "rescuing" flies by making them heterosexual.

[Mangetout]

Neat. Link (http://www.livescience.com/animals/071209-fly-genes.html)

Turns out that in fruit flies at least, it is linked to perception of scents and some other factors. Another nail in the coffin of the old homosexuality is a learned behaviour argument. :cool:
That seems like a massive stretch of assumption. Fruit flies are pretty different from humans, or just mammals, or just vertebrates - is there even any evidence that the phenomenon described as homosexuality here in fruit flies is in any way related to the phenomenon of homosexuality in humans, other than the outward fact that it appears to result in attempted copulation with the same sex?

[Fiveyearlurker]

Unless I'm missing it, I think there is an alternate explanation. The only mention of the courtship behavior in these gb flies is this:

"Based on a striking increase in homosexual courtship displayed by gb mutant flies (Grosjean et al., unpublished results), we named the predicted gene CG6070"genderblind."

I would sort of like to see how they did this experiment, but it isn't discussed in the paper in J. Neurosci. It seems like all they did was put the male flies into tubes with other male flies and note that the gb flies are copulating with same sex partners more often than wild type flies in the same situation.

The correct way to do this experiment is to put the gb flies with 50% male flies and 50% female flies and measure whether they have an increase preference for the same sex flies; that would be more akin to human sexuality than if they are merely unable to differentiate male from female (the flies, not the people!).

Again, they might have done it this way, but it doesn't sound like it and the methods are not outlined in the methods section.

At least if I were a reviewer....

(not doubting that homosexuality is biological, merely doubting that this study is conclusive)

[Voyager]

That seems like a massive stretch of assumption. Fruit flies are pretty different from humans, or just mammals, or just vertebrates - is there even any evidence that the phenomenon described as homosexuality here in fruit flies is in any way related to the phenomenon of homosexuality in humans, other than the outward fact that it appears to result in attempted copulation with the same sex?
Not so different as you might think. (http://www.nih.gov/news/NIH-Record/10_03_2000/story05.htm)

Not to mention that 70% of genes found in the flies are found in us. Cite. (http://archives.cnn.com/2000/NATURE/03/23/fruit.fly.genome/index.html) True we're a mite bigger, and a mite smarter, and we don't have wings, but we're similar in a lot of ways.

[Mangetout]

Not so different as you might think. (http://www.nih.gov/news/NIH-Record/10_03_2000/story05.htm)

Not to mention that 70% of genes found in the flies are found in us. Cite. (http://archives.cnn.com/2000/NATURE/03/23/fruit.fly.genome/index.html) True we're a mite bigger, and a mite smarter, and we don't have wings, but we're similar in a lot of ways.
I'm thinking that behaviour probably isn't all that high on the list of ways in which we're similar.

I agree with Fiveyearlurker - I don't deny a genetic component to homosexuality in humans, but I just don't think this demonstrates it - and I think leaping to that conclusion does more harm than good to the argument for a genetic component.

[nameless]

Hey I actually did a talk on this subject! Not this paper in particular though.

There's been a whole host of genes identified in fruit flies that affect sexual behavior--hermaphrodite, doublesex, and most notably fruitless (har!). Some of these also affect external sexual structure morphology to varying degrees, so it's not clear that these flies are really "gay" so much as you've affected sexual differentiation. IIRC, fruitless was a notable exception in that the flies were morphologically male, but engaged in male-directed behavior. Turned out the fruitless mutation affected a sexually dimorphic ganglion in the fly brain that was responsible for regulating this type of behavior.

Now.

Find me that ganglion in the human brain.

Humans are way more complex, and I wouldn't jump all over this and say "Ergo, this is why humans are gay." I do think it suggests that sexual behavior (hell, behavior in general) is biologically determined, and that humans, while more complex than flies, are still governed by deterministic molecular factors. But that's just the paradigm that I operate from in general.

[Acid Lamp]

Humans are way more complex, and I wouldn't jump all over this and say "Ergo, this is why humans are gay." I do think it suggests that sexual behavior (hell, behavior in general) is biologically determined, and that humans, while more complex than flies, are still governed by deterministic molecular factors. But that's just the paradigm that I operate from in general.

I wouldn't say that either, but any good reproduceable scientific research that demonstrates a concrete biological reason for homosexuality is excellent. Hopefully, the weight of the evidence will eventually squash the cultural bigotry.

[John Mace]

I wouldn't say that either, but any good reproduceable scientific research that demonstrates a concrete biological reason for homosexuality is excellent. Hopefully, the weight of the evidence will eventually squash the cultural bigotry.
Why? We need to be completely dispassionate when doing science. If you want a certain outcome, you're not doing good science. If it turns out that being gay is not biological in nature, that's neither good nor bad. We figure out where we go from there.

That being said, I think most of the evidence we have to date make the biological hypothesis much more likely. But we're not quite at the point of knowing.

[Acid Lamp]

Why? We need to be completely dispassionate when doing science. If you want a certain outcome, you're not doing good science. If it turns out that being gay is not biological in nature, that's neither good nor bad. We figure out where we go from there.

That being said, I think most of the evidence we have to date make the biological hypothesis much more likely. But we're not quite at the point of knowing.

It is just easier on the whole if it IS a biological factor. Would it not be nice if we KNEW that it simply was the way that someone was born, like blue eyes or red hair? It certainly would go a long way to helping to eliminate the cultural problems that we still wrestle with regarding the issue.

[John Mace]

It is just easier on the whole if it IS a biological factor. Would it not be nice if we KNEW that it simply was the way that someone was born, like blue eyes or red hair? It certainly would go a long way to helping to eliminate the cultural problems that we still wrestle with regarding the issue.
I don't want it do be any different than it is. I can't imagine wanting reality to be something that it isn't. Maybe I've just been doing science too long.

In fact, I suspect your own bias has shaped the way you are interpreting this data.

[nameless]

It is just easier on the whole if it IS a biological factor. Would it not be nice if we KNEW that it simply was the way that someone was born, like blue eyes or red hair? It certainly would go a long way to helping to eliminate the cultural problems that we still wrestle with regarding the issue.Would it? Lets say we had a complete understanding of the genetic basis of sexuality, such that we could predict a fetus's future sexuality with reasonable accuracy in utero. You don't forsee some uncomfortable implications of the availability of that knowledge in this sociopolitical climate?

Which is not to say that I think such a thing is possible, feasible, or desirable but to say that understanding the biology of this will cure all of the social misunderstandings regarding homosexuality is absurd.

[emmaliminal]

Personally, I would VERY MUCH like to know how to persuade successive generations of fruit flies in my house to be homosexual. There would be many less of them in a few days, and the ones that were left wouldn't be nearly as insistent on watching NASCAR.

Sorry, had to be done. Really do have a fruit fly infestation.

[ShibbOleth]

Would it? Lets say we had a complete understanding of the genetic basis of sexuality, such that we could predict a fetus's future sexuality with reasonable accuracy in utero. You don't forsee some uncomfortable implications of the availability of that knowledge in this sociopolitical climate?


It would be interesting if you could predict, with close to 100% accuracy, genetic predisposition to homosexuality, but it proved very difficult to affect the outcome (sort of like baldness - we're fairly sure why it occurs but can't do much about it to this point). Especially since the folks who are most fervently anti-homosexual are often the most fervently anti-abortion. Might make them change one view point or the other.

[Acid Lamp]

I don't want it do be any different than it is. I can't imagine wanting reality to be something that it isn't. Maybe I've just been doing science too long.

In fact, I suspect your own bias has shaped the way you are interpreting this data.

Certainly it has, but I am not a scientist doing research on the issue. Frankly, I can not imagine anyone researching anything simply for the sake of it. Nor anyone receiving funding for pure, non applicable studies either. Most research is conducted with some idea of the eventual applications or ramifications of the results. Good science is conducted without bias, but as an end user of results I don't have review it as dispassionately.

The data to me simply says that in fruit flies at least there certainly is a biological component to sexual behavior, cool beans. That means to me that we probably are not too far away from demonstrating the same sorts of interactions in vertebrates. Then mammals, then hominids and so on. That has huge ramifications for us as a species and how we view and deal with homosexuality.

[Acid Lamp]

Would it? Lets say we had a complete understanding of the genetic basis of sexuality, such that we could predict a fetus's future sexuality with reasonable accuracy in utero. You don't forsee some uncomfortable implications of the availability of that knowledge in this sociopolitical climate?

Which is not to say that I think such a thing is possible, feasible, or desirable but to say that understanding the biology of this will cure all of the social misunderstandings regarding homosexuality is absurd.

I never said it would be a panacea for all of society's woes regarding homosexuality, only that such knowledge would be of great help in forwarding acceptance and dissuading intolerance. It would invalidate the "you chose to be gay" camp's argument entirely.

[Indistinguishable]

It's true that strong knowledge of a deeply ingrained biological basis for homosexuality would go a long way towards societal acceptance of homosexuality. Which is kind of sad. Personally, I would love to see a world where people felt that, even if homosexuality had no biological basis, even if it was, of all things, a completely conscious choice(!), there would still be nothing wrong with it.

[John Mace]

The data to me simply says that in fruit flies at least there certainly is a biological component to sexual behavior, cool beans. That means to me that we probably are not too far away from demonstrating the same sorts of interactions in vertebrates. Then mammals, then hominids and so on. That has huge ramifications for us as a species and how we view and deal with homosexuality.
Not necessarily. For instance, we're a lot more closely related to alligators than fruit flies. A lot more closely. And yet alligators use temperature to determine the sex of their offspring, not genes.

Although the evidence for a biological basis for human sexual orientation is very strong, we're can be pretty certain that it isn't genetic (or not wholly genetic). And if we do find a simple biological basis, like genetics, then are you going to jump for joy when people start aborting babies with the "gay gene"? Or, if parents give anti-gay drugs to children who exhibit signs of being gay?

Any answer is going to generate problems. It's not the particular mechanism that creates the problems but what we do with the knowledge.

[Acid Lamp]

Although the evidence for a biological basis for human sexual orientation is very strong, we're can be pretty certain that it isn't genetic (or not wholly genetic). And if we do find a simple biological basis, like genetics, then are you going to jump for joy when people start aborting babies with the "gay gene"? Or, if parents give anti-gay drugs to children who exhibit signs of being gay?

Any answer is going to generate problems. It's not the particular mechanism that creates the problems but what we do with the knowledge.

bolding mine

That is absolutely true.

Here is where I am certain to get flamed, No I wouldn't have any more of a problem with the termination of a "gay" pregnancy, then one for any other reason. Further, if gene therapy, or a drug could be developed to give those people who do have serious issues with their sexuality a chance at trying the other side of the fence, I have no issue with that either.

[John Mace]

Here is where I am certain to get flamed, No I wouldn't have any more of a problem with the termination of a "gay" pregnancy, then one for any other reason. Further, if gene therapy, or a drug could be developed to give those people who do have serious issues with their sexuality a chance at trying the other side of the fence, I have no issue with that either.
OK-- I'm not going to flame you.

I'm OK with abortion on demand for any reason at all, up until the point of viability of the fetus. If a woman wants to abort her fetus because it might have the wrong hair color, that's her perogative. I might think she's shallow, but so what?

If a gay person decides that he wants to take a drug to be straight (assuming there is such a drug), then good for him/her. Technology should help us be who we want. Of course, things are rarely that easy-- side effects might be a big problem. Or people might still discriminate against people who are "straight by chemicals".

So, if you feel that way, too, what difference does it make what the mechanism is? If it turns out to be learned, it can be unlearned.

[Acid Lamp]

So, if you feel that way, too, what difference does it make what the mechanism is? If it turns out to be learned, it can be unlearned.

snip>

Not necessarily. There a plenty of psychological conditions that can only be moderated, and not entirely corrected. A biological answer would allow those happy with themselves to better defend against intolerance. A psychological answer would, I suppose, be just as likely to cause any degree of new intolerance as well. Either way, a definitive answer would allow us to pursue logical avenues for re-orientation for those who want it, and help us to better understand those who do not.

[Fiveyearlurker]

Certainly it has, but I am not a scientist doing research on the issue. Frankly, I can not imagine anyone researching anything simply for the sake of it. Nor anyone receiving funding for pure, non applicable studies either. Most research is conducted with some idea of the eventual applications or ramifications of the results.


I would argue that, at least in the biological sciences, that this is not true. That the majority of research is done with no application in mind.

[John Mace]

snip>

Not necessarily. There a plenty of psychological conditions that can only be moderated, and not entirely corrected. A biological answer would allow those happy with themselves to better defend against intolerance. A psychological answer would, I suppose, be just as likely to cause any degree of new intolerance as well. Either way, a definitive answer would allow us to pursue logical avenues for re-orientation for those who want it, and help us to better understand those who do not.
For those basing their views on religions doctrine, it won't make any difference. And I think you overestimate peoples' willingness to have rational discussions about emotional issues.

[CarnalK]

For those basing their views on religions doctrine, it won't make any difference.
I don't see scientific research changing the mind of people who are religiously humanist, either. Scientists could discover a specific chemical that causes human "gayness" and it wouldn't change a thing in social libertarians defence of homosexuality.

Not to slam gay people. I think whatever's screwed up in them is not societally damaging. It's just the defenses of "gayness" are usually ridiculous. Desperate attempts are made to make it out like maybe a gay uncle is evolutionary benefit to the species. There's got to be some incredibly useful reason gay people exist, right? :rolleyes:

[Indistinguishable]

The only defense homosexuality need be given is that no one has ever come up with a rationally indicting moral argument against homosexual activity; it should be considered acceptable by default. Which is why I think it's kind of sad (though perhaps pragmatically advisable all the same) to make arguments which ground its defense in its biological mode of origin or any such things; as if, were the research to come out slightly differently, it would then be properly considered morally suspect. Such defenses are too contingent; they merely attempt to slap a band-aid on the problem of homophobia, rather than truly dealing with the underlying issue: that people somehow misguidedly think harmless consensual acts of this type can be immoral (or, alternatively, that they have some bizarre idea of harm which can be wreaked by homosexuality). Whatever the origin of homosexuality, whether or not it is biological, fixed, and/or involuntary in nature, these views are disastrously mistaken, and the proper counterarguments are ones which don't depend on any such premises about the mechanism of homosexuality. The sort of "defenses" homosexual activity demands should be just the same as, say, the "defenses" dancing demands: sure, the latter is very much a learned voluntary behavior which can easily be avoided, but that in no ways weakens the fact that there's nothing wrong with it, and in no way mitigates the evil of attempts to punish it.

[Malacandra]

Indeed. And the flip side of that would be to point out that we don't consider, say, thievery to be excusable simply because the individual is born with a predisposition to steal; either the urge needs to be controlled for the good of society or it does not, and if it does not then there is no reason to be prejudiced against acting upon it, and if it does then it is no use pleading the excuse that one was born that way.

[CarnalK]

As far as I can tell I think I agree with you completely*, Indistinguishable. Except for that last sentence. Unless you come from some bizarrely puritan region, dancing is a bad analogy to use, Dirty Dancing notwithstanding.


*eta: like i said "is not societally damaging"

[Indistinguishable]

Well, I chose dancing as an analogy precisely because we can all agree that belief in its immorality is bizarrely puritan, even though it's a completely voluntary behavior which admits no attempt at a "But it's in my genes!" defense. [Not that it really matters for the analogy, but I think there have been significant contemporary societies which prohibited dancing as immoral (under the influence of Wahhabism, for example).]

Also, that's a very good point, Malacandra, although I think maybe some people would (misguidedly, I would say) get carried away if it were to be discovered that there were some genetic factor which significantly tracked predisposition to steal. You'd probably hear a whole lot of irrelevant blather about free will vs. determinism in the ensuing debates about morality, at the very least.

[nameless]

I would argue that, at least in the biological sciences, that this is not true. That the majority of research is done with no application in mind.Fiveyearlurker is correct IMO. The research I do has no human applications that I can forsee whatsoever.

But that's the beauty of basic science, it often has unforseen consequences.


Not to slam gay people. I think whatever's screwed up in them is not societally damaging. It's just the defenses of "gayness" are usually ridiculous. Desperate attempts are made to make it out like maybe a gay uncle is evolutionary benefit to the species. There's got to be some incredibly useful reason gay people exist, right?Man, what? What's "screwed up" about gay people? Where are you going with this?

[Mangetout]

...If it turns out to be learned, it can be unlearned.
I don't see why that must necessarily be the case - It would probably be true to say that if it's learned, we could concievably prevent it being learned in future generations, but I don't think it can be true that something learned during development can be unlearned later. Could you unlearn the English language?

[Malacandra]

I don't see why that must necessarily be the case - It would probably be true to say that if it's learned, we could concievably prevent it being learned in future generations, but I don't think it can be true that something learned during development can be unlearned later. Could you unlearn the English language?
Anecdotally, I believe it is the case that people who learn a new language to the point that they are able to think in it, and who use it to the exclusion of their mother tongue, can actually lose facility with their mother tongue. I'll go no further than the qualified expression above, since I have neither a cite nor first-hand experience, but I'd be interested to hear from any non-native speakers who may be able to confirm this.

Man, what? What's "screwed up" about gay people? Where are you going with this?Well, insofar as homosexuality is not so much an attraction towards the same sex as a revulsion towards the opposite, to the point of being unable to breed, you have to admit that it would be a pretty harmful predisposition on the face of it. It's perfectly possible that there are either counterbalancing advantages to homosexuality itself (gay uncle theory) or to the genetic marker (sickle cell analogy), but that's another topic.

[CarnalK]

Man, what? What's "screwed up" about gay people? Where are you going with this?
Well, it kind of goes without saying that they are sexually screwed up from a physiological perspective. They are inclined to be functionally sterile. No moral judgment being made.

[DrCube]

Anybody who accepts the "being gay is a choice" argument has already given up the fight. Eating broccoli is choice, too, but nobody thinks there is anything wrong with it. Whatever floats your boat.

The question is whether or not being gay is a bad thing (it isn't), so that finally concluding one way or another if it is biological in origin will not settle anything. If people "chose" to be black, would that make racism any more acceptable?

[Argent Towers]

No shit. I was just going to say that the fact that we understand "race" as a physical trait to be completely genetic and biologically-based hasn't removed the problem of racism from our society. Why would it be any different with sexuality?

As for the whole fruit fly thing, I'm thinking the only way to definitively figure out what "homosexuality" means in this context would be to ask the fruit fly. Until that's possible, I don't think we can draw many conclusions from this.

[Mangetout]

Anybody who accepts the "being gay is a choice" argument has already given up the fight. Eating broccoli is choice, too, but nobody thinks there is anything wrong with it. Whatever floats your boat.

The question is whether or not being gay is a bad thing (it isn't), so that finally concluding one way or another if it is biological in origin will not settle anything. If people "chose" to be black, would that make racism any more acceptable?
I agree - hanging our hopes on the idea that this or that piece of research will convince those who need convincing is just unrealistic - after all, a significantly overlapping group of the same people are still in massive denial about the fossil record and a whole bunch of other science - why would they accept scientific evidence that homosexuality is 100% non-choice? (if such evidence were possible)

[mr. jp]

What Fiveyearlurker said.

Also, to what degree does homosexuality increase with the mutation? I mean, that homosexuality is partly genetic is nothing new.

[John Mace]

I would argue that, at least in the biological sciences, that this is not true. That the majority of research is done with no application in mind.
I don't think that is the actual issue we were discussing, though. The majority of research is (and should be) done without a desire on the researcher's part for the result to come out a certain way. When you attack a problem wanting a certain result, you've got a good chance you will miss something important that doesn't fit your bias. I can do research with a certain application in mind (curing cancer), but I shouldn't be predisposed to look only for a certain type of cause (genetic vs environmental).

As for homosexuality in humans, I wouldn't be surprised to find that there was a combination of things that caused it, or that there might be different causes under different conditions.

[Contrapuntal]

Not to mention that 70% of genes found in the flies are found in us. Cite. (http://archives.cnn.com/2000/NATURE/03/23/fruit.fly.genome/index.html) True we're a mite bigger, and a mite smarter, and we don't have wings, but we're similar in a lot of ways.Well, we share 75% of our genes with pumpkins. I'm not sure that is a reliable test of similarity.


That's the difference between Darwin and Crick. Evolution, whatever offense it gives, by definition emphasizes how far man has come from his tree-swinging forebears. DNA, in contrast, seems reductive. Man and chimp share 98.5 percent of their genetic code, which would be no surprise to Darwin. But we also share 75 percent of our genetic makeup with the pumpkin. The pumpkin is just a big, ridged, orange lump lying on the ground all day, like a fat retiree on the beach in Florida. But other than that he has no discernible human characteristics until your kid carves them into him.

From here. (http://www.theatlantic.com/doc/200410/steyn) (Whole article may not be available online.)

[Der Trihs]

Well, insofar as homosexuality is not so much an attraction towards the same sex as a revulsion towards the opposite, to the point of being unable to breed, you have to admit that it would be a pretty harmful predisposition on the face of it. :rolleyes: And insofar as homosexuality causes spontaneous combustion it's a bad thing too. Homosexuals have plenty of attraction towards their own sex, and no special revulsion that's I've ever heard of; certainly none more extreme than straights have toward their own sex. Show a photo of a naked man to a lesbian and she's more likely to roll her eyes at you than cower like a vampire presented with a cross.

And homosexuals can and do have children if they feel like it. And plenty of straights can't or don't want to have children. How is not having children "harmful" ? We have far too many people, not too few.

[Malacandra]

:rolleyes: Fine, there is no biological advantage in favour of a predisposition to having sex with creatures with which it is possible to breed - hence no corresponding biological disadvantage to the contrary case. Gotcha.

[LonesomePolecat]

How is not having children "harmful" ? Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe.

[Revenant Threshold]

Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe. It's a serious danger now? Really?

[John Mace]

The other thing to keep in mind is that homosexuality is just one type of sexual behavior that seems abnormal. Not that I'm equating homosexuality with deviancy, but there are plenty of humans attracted to pre-pubescent children (of either sex), humans who get off on S/M or B/D practices, etc. Do we know what causes any of those predispositions? If we were to find that pedophilia was completely biological in origin, would society feel better about it?

Not to mention that there are plenty of societies where homosexual acts are* common, even with straight people. We're very far from cracking this nut, and I suspect a full understanding of this very complex behavior is not going to occur any time soon.

*or "were", in the case of societies that no longer exist (like Ancient Greece)

[LonesomePolecat]

It's a serious danger now? Really?Yes, it is. Are you really saying you have been totally unaware of the demographic death spiral Europe has been locked into for some time now? You haven't heard anything about the "birth dearth" or the "grayby boom"? You haven't heard about how concerned political and business leaders are about the political and economic troubles it's going to cause? Japan is running into demographic troubles because of the drastic drop in its fertililty rates as well. You'd have to have been living in a cave on Mars for the last twenty years not to be aware of this.

[Fiveyearlurker]

As for homosexuality in humans, I wouldn't be surprised to find that there was a combination of things that caused it, or that there might be different causes under different conditions.

I have very little doubt at all that this is correct. My genes did not say that I would be 5'7". My genes said that I would be somewhere between 5'3" and 5'10". I had no chance at all to be Shaq, and none at all to be Tattoo. My environment narrowed that number down to my final height. What I ate. What illnesses I had. The exercises and stresses that my body endured as it grew. My hormone levels.

Homosexuality is likely the same. There is a spectrum. Your genes put you somewhere on that spectrum between straight and gay and something about environment made the final call on whether you were over the threshhold for gay or not (or somewhere in between).

I would have little idea what those environmental cues are. I'm not talking about parents making you watch The Birdcage at an early age or something silly. More like hormone levels in the womb, but potentially things that you are exposed to at an early age as well. Likely a combination of many factors all making that final call.

[John Mace]

Homosexuality is likely the same. There is a spectrum. Your genes put you somewhere on that spectrum between straight and gay and something about environment made the final call on whether you were over the threshhold for gay or not (or somewhere in between).

I would have little idea what those environmental cues are. I'm not talking about parents making you watch The Birdcage at an early age or something silly. More like hormone levels in the womb, but potentially things that you are exposed to at an early age as well. Likely a combination of many factors all making that final call.
It might not be genetic at all-- the biological component could be entirely due to conditions in the womb. That might make it genetic in the sense that the mother's genes come into play, but not yours (directly). It could be that we're genetically capable of being straight or gay or anything in between.

[Steve MB]

Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe.

That claim seems extremely dubious, given that even the slowest-breeding European culture is cranking out orders of magnitude more children than many ancient cultures that survived for centuries.

[Anne Neville]

Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe.

As we all know, there's no way to transmit culture other than having children. This explains why McDonald's and Coca-Cola are doing so badly when they try to market their products to people with no American blood...

[Mangetout]

So. Being homosexual means you get turned on by fruit flies?

I KNEW it!

[Malacandra]

That claim seems extremely dubious, given that even the slowest-breeding European culture is cranking out orders of magnitude more children than many ancient cultures that survived for centuries.

"Orders of magnitude"? The survival rate may be way up, but I thought in some places the actual birth rate was below replacement. Granted, for most of human history the net breeding rate just barely made it above replacement, but lower is still worse.

[John Mace]

"Orders of magnitude"? The survival rate may be way up, but I thought in some places the actual birth rate was below replacement. Granted, for most of human history the net breeding rate just barely made it above replacement, but lower is still worse.
Yes, some European countries are below that rate. They might have to (oh, the horrors!!) allow more immigration to keep their population afloat. Same for the Japanese.

[Fiveyearlurker]

It might not be genetic at all-- the biological component could be entirely due to conditions in the womb. That might make it genetic in the sense that the mother's genes come into play, but not yours (directly). It could be that we're genetically capable of being straight or gay or anything in between.

That would still make it genetic (at least in my book), even if 100% true. It would just be genetic, once removed.

[nameless]

Yes, it is. Are you really saying you have been totally unaware of the demographic death spiral Europe has been locked into for some time now? You haven't heard anything about the "birth dearth" or the "grayby boom"?Can you show that increasing rates of homosexuality in Europe are the cause of this demographic collapse?

Interesting little abstract here, don't have access to the journal yet.

However, gay men have fewer children than heterosexual men. Increased fecundity in the biological relatives of gay men could offset this selection pressure. We measured family size in gay (n = 301) and heterosexual (n = 404) men, attending clinics for sexually transmitted infections. The main outcome measure was the number of each man's uncles and aunts, first cousins, siblings, nephews and nieces, and his own children. With the exception of the participants' own offspring, mean family size of each category of relatives was significantly larger for gay men (paternal and maternal total OR = 1.02, CI = 1.01-1.03). This remained the case after adjustment for other predictors of family size (paternal and maternal total OR = 1.02, CI = 1.00-1.03). (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=15772775&ordinalpos=56&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum)(bolding mine)

So maybe those talking about how homosexuality will lead to the collapse of the reproduction rate are missing ancillary effects of "homosexuality genes" in families?

[John Mace]

That would still make it genetic (at least in my book), even if 100% true. It would just be genetic, once removed.
But I think that is very different from what pops into people's heads when you use the term. Hence, I think the qualification is necessary.

[Shodan]

So maybe those talking about how homosexuality will lead to the collapse of the reproduction rate are missing ancillary effects of "homosexuality genes" in families?
Correlation != causation, of course, until you can demonstrate that the same genetic conditions that "cause" homosexuality also "cause" larger family sizes.

Regards,
Shodan

[John Mace]

So maybe those talking about how homosexuality will lead to the collapse of the reproduction rate are missing ancillary effects of "homosexuality genes" in families?
I would be very suspicious of any such study done on an industrialized population, since reproduction in such a society is largely a matter of personal choice and not genetic fitness.

[nameless]

Correlation != causation, of course, until you can demonstrate that the same genetic conditions that "cause" homosexuality also "cause" larger family sizes.Well okay then, if our model is that homosexuality leads to demographic collapse, I think there are some predictions that come out of that model.

1) Cultures with very severe attitudes towards homosexuality will exhibit higher birth rates; they will be protected against demographic collapse.
2) Cultures with very permissive attitudes towards homosexuality will exhibit lower birth rates; they will be susceptible to demographic collapse.
3) These effects must be independent of economic and educational factors.

I think 3 is the key here; I'm pretty sure birth rate decreases as economic success and quality of education increase.

ETA: And you know, it's also not a given that cultural pressure will be sufficient to repress homosexual behavior, so ideally, you'd be able to show that there was actually (A) a decline in same-sex sexual activity in individuals in response to cultural pressure or (B) that same-sex sexual activity itself was inversely proportional to birth rate.

I would be very suspicious of any such study done on an industrialized population, since reproduction in such a society is largely a matter of personal choice and not genetic fitness.I'm confused. I think the authors acknowledge this caveat (I didn't quote part of the abstract that was basically "maybe the families with gay people overcompensated by popping out more kids due to social pressures"), but you don't find it plausible that gene products that contribute to homosexuality also, in some way, contribute to fertility, desire to have children, or parenting efficacy or something?

[Revenant Threshold]

Yes, it is. Are you really saying you have been totally unaware of the demographic death spiral Europe has been locked into for some time now? You haven't heard anything about the "birth dearth" or the "grayby boom"? You haven't heard about how concerned political and business leaders are about the political and economic troubles it's going to cause? Japan is running into demographic troubles because of the drastic drop in its fertililty rates as well. You'd have to have been living in a cave on Mars for the last twenty years not to be aware of this. I have indeed heard of all these things. I'm not suggesting you're wrong in saying there's a drop in the birth rate. I'm suggesting you're wrong to say it's a serious danger now. In a few generations, if things stay the same (or get worse) perhaps then it might be a danger. Now we're in serious danger? We may be heading towards something, but we're not there yet.

[Triskadecamus]

Man, I am so . . . nonplussed.

Why the heck would I care if a fruit fly was homosexual? I don't even care if the President is a homosexual!

Did I pay for this research?

Tris

[John Mace]

I'm confused. I think the authors acknowledge this caveat (I didn't quote part of the abstract that was basically "maybe the families with gay people overcompensated by popping out more kids due to social pressures"), but you don't find it plausible that gene products that contribute to homosexuality also, in some way, contribute to fertility, desire to have children, or parenting efficacy or something?
It's certainly plausible. I just wonder how you get the signal out of the noise in such a study. If you could measure actual fertility in those families, that would be more convincing. But family size is determined by lots of factors, and isolating those factors is problematic, to say the least.

[nameless]

It's certainly plausible. I just wonder how you get the signal out of the noise in such a study. If you could measure actual fertility in those families, that would be more convincing. But family size is determined by lots of factors, and isolating those factors is problematic, to say the least.Regardless of the particular mechanism of this familial size effect though, I'd say it is evidence against the insinuation that homosexuality will inevitably lead to lower birth rate and a population crisis. I certainly agree that there are probably other factors at work here.

[John Mace]

Regardless of the particular mechanism of this familial size effect though, I'd say it is evidence against the insinuation that homosexuality will inevitably lead to lower birth rate and a population crisis. I certainly agree that there are probably other factors at work here.
I agree that it would be incorrect to state that homosexuality will inevitably lead to lower birth rates. But something that occurs as rarely as homosexuality does, needn't have any selective benefit just because it persists in a population. Lots of seemingly adverse traits, like actual sterility, occur at about the same frequency. You don't see people tripping over themselves looking for what positive effect sterility might have on a population.

[CarnalK]

Regardless of the particular mechanism of this familial size effect though, I'd say it is evidence against the insinuation that homosexuality will inevitably lead to lower birth rate and a population crisis. I certainly agree that there are probably other factors at work here.
Kind of an odd choice having all the subjects come from sexual infection clinics, though.

So if Aliens released a chemical with a similar effect on humans as to the fruit flies in the OP and human rates of homosexuality shot up to 90%+ we all agree this would be a bad thing? When we can't (horror of horrors) just ship in some extra Turkish immigrants to solve the problem?

eta: You don't see people tripping over themselves looking for what positive effect sterility might have on a population.
You haven't heard of the "sterile uncle" theory? ;)

[Anne Neville]

So if Aliens released a chemical with a similar effect on humans as to the fruit flies in the OP and human rates of homosexuality shot up to 90%+ we all agree this would be a bad thing? When we can't (horror of horrors) just ship in some extra Turkish immigrants to solve the problem?

But homosexual humans do reproduce. Some of them do so by sleeping with members of the opposite sex, even though they would prefer to sleep with a member of their own sex. Some of them reproduce these days using technologies such as artificial insemination. Homosexuality isn't a complete barrier to reproduction.

[CarnalK]

But homosexual humans do reproduce. Some of them do so by sleeping with members of the opposite sex, even though they would prefer to sleep with a member of their own sex. Some of them reproduce these days using technologies such as artificial insemination. Homosexuality isn't a complete barrier to reproduction.
I didn't say it was a complete barrier. I said 90%+ homosexuality would be a "bad thing". I hate to break it to you but artificial insemination costs a lot. Sure the poor people could break out the turkey basters and some stoic gay men will impregnate women for king and country but humans are lazy. They'd for the most part prefer just to have sex and let the race die off, istm.

[nameless]

So if Aliens released a chemical with a similar effect on humans as to the fruit flies in the OP and human rates of homosexuality shot up to 90%+ we all agree this would be a bad thing?Of course. I'm not really comfortable with the idea of aliens massively dumping behavior-altering chemicals on our planet. But this hypothetical has minimal relevance to the question of whether society should care whether or not its members engage in same-sex activity, since (1) it's not clear that family size correlates negatively with incidence of same-sex activity (at least at the rate of activity we have right now) and I've presented evidence to suggest the opposite is actually true and (2) I don't think we have to worry extensively about the extinction of the human race due to low reproduction at this point.

[CarnalK]

Of course. I'm not really comfortable with the idea of aliens massively dumping behavior-altering chemicals on our planet. But this hypothetical has minimal relevance to the question of whether society should care whether or not its members engage in same-sex activity, since (1) it's not clear that family size correlates negatively with incidence of same-sex activity (at least at the rate of activity we have right now) and I've presented evidence to suggest the opposite is actually true and (2) I don't think we have to worry extensively about the extinction of the human race due to low reproduction at this point.
I don't think anyone really put forward that question, though. LonesomePolecat just said choosing a low birth rate has societal ramifications and everyone seemed to think he was saying homosexuality needing addressing for that reason. Unless he has some history on the subject, I don't think he was extending his point that far.

Is it possible, btw, that your cited study really shows that gay men with a sexual infection are more likely to come from larger families?

[Anne Neville]

Sure the poor people could break out the turkey basters and some stoic gay men will impregnate women for king and country but humans are lazy. They'd for the most part prefer just to have sex and let the race die off, istm.

They don't do it for king and country. They do it because they want kids. People do want kids independent of wanting heterosexual sex. The best evidence for this is the existence of fertility treatments and adoption.

[Indistinguishable]

The idea that there's something "wrong" with homosexuality because birth rates may go up if gay people turned straight is a little weird, too. Even besides Anne Neville's insightful point, this sort of thinking seems to support saying there's something "wrong" with not wanting kids, or only wanting to have one kid when one could have three instead, or so on. I certainly don't think there's anything wrong with any of that. At least, not for any useful sense of "wrong".

[nameless]

Is it possible, btw, that your cited study really shows that gay men with a sexual infection are more likely to come from larger families?Absolutely. It's findings have been replicated several times however. Here are some excerpts from a more recent paper reviewing this phenomenon.

Recently, one study in an Italian sample shed further light on the Darwinian paradox of male homosexuality by demonstrating that female maternal relatives of homosexual men (n = 98) had higher fecundity than female maternal relatives of heterosexual men (n = 100), a difference not found in paternal relatives, and that homosexuals had more maternal but not paternal male homosexual relatives (Camperio-Ciani, Corna, & Capiluppi, 2004).

(...)

McKnight and Malcolm (2000) reported elevated maternal line fecundity as a function of greater numbers of aunts in homosexual men (n = 60) compared to heterosexual men (n = 60).

(...)

King et al. (2005) reported on a sample from the United Kingdom (UK) comprising 301 homosexual and 404 heterosexual men recruited from clinics for sexually transmitted infections. They reported mean family size to be significantly larger for homosexual men and that homosexual men had significantly more older brothers and older sisters than did heterosexual men.

(...)

Finally, Widmayer and Ellis (2005) reported that the parents of homosexuals (males and females) reported having significantly fewer siblings compared to parents of heterosexuals (males and females). Thus far, three studies have found greater familial fecundity among homosexual men, two of these attributing it to a female line effect (Camperio-Ciani et al., 2004; McKnight & Malcolm, 2000), one to more or less both lines (King et al., 2005), while one further study found elevated fecundity among heterosexuals as reported by their parents (Widmayer & Ellis, 2005).So one study contradicts the other three, but I think taken together, these studies support my point, which is: I doubt that same-sex behavior, occurring at the rate it does today, negatively affects family size.

[Shodan]

Regardless of the particular mechanism of this familial size effect though, I'd say it is evidence against the insinuation that homosexuality will inevitably lead to lower birth rate and a population crisis. I certainly agree that there are probably other factors at work here.
But I don't see anyone making this insinuation. Lonesome Polecat mentioned that Japan and some European countries were breeding below replacement. No one is suggesting that this is due to homosexuality.

Regards,
Shodan

[nameless]

But I don't see anyone making this insinuation. Lonesome Polecat mentioned that Japan and some European countries were breeding below replacement. No one is suggesting that this is due to homosexuality.

Regards,
ShodanHere's the conversational sequence that made me :dubious: a little--Well, insofar as homosexuality is not so much an attraction towards the same sex as a revulsion towards the opposite, to the point of being unable to breed, you have to admit that it would be a pretty harmful predisposition on the face of it.
And homosexuals can and do have children if they feel like it. And plenty of straights can't or don't want to have children. How is not having children "harmful" ? We have far too many people, not too few.Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe.But at any rate, I can see how I might have read too much into this and I will let it drop if nobody's going to take up that position.

[Nava]

Anecdotally, I believe it is the case that people who learn a new language to the point that they are able to think in it, and who use it to the exclusion of their mother tongue, can actually lose facility with their mother tongue. I'll go no further than the qualified expression above, since I have neither a cite nor first-hand experience, but I'd be interested to hear from any non-native speakers who may be able to confirm this.

Well, I've never gone more than a few days at a time without speaking Spanish, but when I've been using English as my primary language for a few months, I start having a particular kind of "can't find the word in this language" problem... if I've been using Spanish as my primary, then I have those problems when using English.



Depression is known to have either
- perfectly reasonable external triggers (exogenic depression), in which case the depression goes away when the trigger does (think of someone being depressed after losing his job), or
- perfectly reasonable if not fully-known biochemical triggers (endogenous depression), in which case the right pill does wonders. Think post-partum depression.

And yet, it's still a hush-hush subject, as much The Illness That Shall Not Be Named as, say, cancer. Therefore, I don't expect people to be any more reasonable about sexual orientation if/when it's ever proven to have a biological origin.

[Der Trihs]

Because if enough people choose not to have them, it becomes more and more difficult, and eventually impossible, for a society to transmit its culture to future generations. This is already a serious danger in Europe.Hardly, it's a benefit ( and one that has little or nothing to do with homosexuals ). Our present population is much too high; we need to lower it. And the moral, acceptable way to do that is a lower birth rate. If anything the problem is that too many people are still having children.

And as said, you don't need children to pass a culture on; it's learned, not genetic.

I didn't say it was a complete barrier. I said 90%+ homosexuality would be a "bad thing". I hate to break it to you but artificial insemination costs a lot. Sure the poor people could break out the turkey basters and some stoic gay men will impregnate women for king and country but humans are lazy. They'd for the most part prefer just to have sex and let the race die off, istm.Except that wouldn't happen. The non-homosexuals would outbreed the homosexuals and in a few generations we'd be back roughly to the ratio we have now; that's how evolution works.

[Steve MB]

"Orders of magnitude"?
Yes, orders of magnitude (http://www.census.gov/ipc/www/worldhis.html).

[CarnalK]

Except that wouldn't happen. The non-homosexuals would outbreed the homosexuals and in a few generations we'd be back roughly to the ratio we have now; that's how evolution works.
Says you, I guess. I think your confidence is seriously misplaced. There would be quite a few hurdles to overcome. First of all, such a massive loss of breeding stock would have serious implication for disease resistance and the emergence of recessive genes. I'm under the impression that humanity is already thought to have a rather non-varied gene pool compared to other animals. Then there is the problem of exactly how society would handle such a turn of affairs. With your pessimistic view of human nature, I'm sure you can imagine some dark scenarios for yourself.


Whatever the case "a few generations" is bizarrely optimistic, IMHO.

[Steve MB]

Says you, I guess. I think your confidence is seriously misplaced. There would be quite a few hurdles to overcome. First of all, such a massive loss of breeding stock would have serious implication for disease resistance and the emergence of recessive genes. I'm under the impression that humanity is already thought to have a rather non-varied gene pool compared to other animals.
That's apparently the result of homo sapiens being reduced to the size of a small-town population when the Toba supervolcano went kerblooey. The conjectured scenario of nine deviated preverts for every one normal God-fearing heterosexual is nothing compared to that.

[Der Trihs]

Whatever the case "a few generations" is bizarrely optimistic, IMHO.Why ? It's a direct implication of the whole "gays are evil child hating monsters" theory. If they don't have children, they will be outbred in a SINGLE generation, by definition.

[CarnalK]

That's apparently the result of homo sapiens being reduced to the size of a small-town population when the Toba supervolcano went kerblooey. The conjectured scenario of nine deviated preverts for every one normal God-fearing heterosexual is nothing compared to that.
Yes, it would be less damaging than that, but since that Volcano die off already happened I'm not sure we can afford another genetic disaster.

Why ? It's a direct implication of the whole "gays are evil child hating monsters" theory. If they don't have children, they will be outbred in a SINGLE generation, by definition.
What the hell are you talking about? I didn't imply that nutjob theory so I can only imagine you are arguing with some warm comforting mental image of the perfect bigot.

[rock party]

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.

[Voyager]

I'm thinking that behaviour probably isn't all that high on the list of ways in which we're similar.

I agree with Fiveyearlurker - I don't deny a genetic component to homosexuality in humans, but I just don't think this demonstrates it - and I think leaping to that conclusion does more harm than good to the argument for a genetic component.
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.

[CarnalK]

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.
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)

[Mangetout]

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.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.

[CarnalK]

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?

[Malacandra]

Yes, orders of magnitude (http://www.census.gov/ipc/www/worldhis.html).

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.

[nameless]

As the apparently more expert John Mace agreed,Ouch, my feelings.

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?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.

[nameless]

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 (http://en.wikipedia.org/wiki/Heterozygote_advantage) or some other mechanism), those will remain in place in individuals who aren't treated for Alzheimer's disease.

[Steve MB]

I know the population's gone through the roof, but that's not because people are having orders of magnitude more children
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.

[CarnalK]

Ouch, my feelings.
I meant more expert than myself. Maybe he's more expert than you, as well.

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."

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.

[jackdavinci]

Another nail in the coffin of the old homosexuality is a learned behaviour argument. :cool:

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).

[nameless]

Maybe he's more expert than you, as well.Undoubtedly. I'm an expert in very few things :cool:

I don't see what new thing I'm measuring.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?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?

It is entirely un-silly to recognize that expression of certain traits may be beneficial up to a point.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.

[kimera]

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.

[CarnalK]

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?

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.

[CarnalK]

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.

[Malacandra]

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.

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!

[Indistinguishable]

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...

[CarnalK]

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,

[Malacandra]

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.

[CarnalK]

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.

[CarnalK]

missed edit window:
Though it could be, it may not really be a "cultural" effect. I know even some of the simplest of creatures change mating behaviour because of environmental or sexual ratio issues.

[Malacandra]

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.

Sure, behaviour's complex. There's every possibility that a couple might decide to have more kids because Brother Joe is showing no sign of having any of his own - especially if the extended family is pooling resources and so the extra kids are affordable. As I thought I'd been saying all along, a putative homosexuality gene could look at first sight like it would have to be a severe defect from the point of view of the reproductive capability of the individual possessing it, and yet be well able to pass itself along for a whole bunch of reasons.

I know even some of the simplest of creatures change mating behaviour because of environmental or sexual ratio issues.

Indeed. It's a well-known factoid (I don't know if the experiment's been discredited) that rats can turn queer if forcibly overcrowded.

[Steve MB]

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
The original subthread was about having enough people to transmit a culture. The fact that absolute rather than per capita numbers are the relevant ones is so blindingly obvious that I thought it would be insulting to spell it out. Evidently I was mistaken.

[Sockmunkey]

The downside of proving biological causation is that the anti-gay crowd's immediate response will be "Great! Now we can get cracking on a genetic cure!".