EPTEvolutionary drive of homosexuality - Page 4
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Vestige
United States303 Posts
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_Darwin_
United States2374 Posts
On November 30 2010 09:15 mikado wrote: Well now, don't forget to quote this form my previous post either: 'And recent studies have affirmed that most of the random events produced in the blastocyst or the foetal stages of development are in correlation with activation/deactivation/variation of portions of the so called junk-DNA sequences.' At the very basic level again, biomolecular interaction --> genetics. Unless you're saying eating bananas (exposure to some chemical, etc) will make your baby gay, I don't see how you can't tie it down to genetics. There's whole fields dedicated to studying genetic influence over complex social behavior, let alone primal instincts and urges; we're way ahead of confirming genetic influence on such processes. It's already been discussed in this thread by multiple posters. http://en.wikipedia.org/wiki/Prenatal_hormones_and_sexual_orientation | ||
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MetalFace
United States75 Posts
On November 30 2010 09:17 Vestige wrote: I don't know if this has already been mentioned, but when a population reaches it's limiting capacity, people will either die or stop reproducing or both because the environment can only sustain so many organisms. Homosexuality prevents reproduction, slowing down the growth of a population to a more controllable rate. I doubt it. If you look at other animals, when their population outgrows their environment they'll continue reproducing as usual but they just die off because there isn't enough food/space/etc. They don't just experience a jolt in homosexuality in order to equalize population. | ||
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MadVillain
United States402 Posts
Or, Homosexuality arises from environmental effects, possibly while the fetus is still in the womb. These effects could be physical, for example increased estrogen levels. Or they could be psychological, the absence of a major male influence during pre-pubescent life. I think its a combination of both, and any genetic factors are likely to be very subtle. Its silly to think that we'll someday isolate a "gay gene." Needless to say I really don't think there is remotely enough research to make any sound conclusions yet. | ||
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mikado
Australia407 Posts
On November 30 2010 09:19 _Darwin_ wrote: It's already been discussed in this thread by multiple posters. http://en.wikipedia.org/wiki/Prenatal_hormones_and_sexual_orientation And so, what then? Hormones are genetically expressed proteins; ergo genetic cause-effect relationship. @Half I'm saying sexual orientation is genetically determined, either directly via genes and variations thereof or indirectly via other homeostatic systems. | ||
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mikado
Australia407 Posts
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Half
United States2554 Posts
On November 30 2010 09:20 mikado wrote: And so, what then? Hormones are genetically expressed proteins; ergo genetic cause-effect relationship. Hormones levels are also highly variable due to environmental influence....... | ||
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ToxNub
Canada805 Posts
An enormous variety of behaviour and physical traits, genetic abnormalities, predispositions etc, are not at all ideal or even beneficial. I thought the obvious and accepted answer is that it was simply random. But not probable enough to hinder the survival of the species, hence they continue to propagate. I mean, I could ask, why do we get cancer? Shouldn't all the cancerous susceptible have already weeded it out? Obviously there's a lot more cancer than there are homos. Ok, so not a great example, since people tend to reproduce before they get cancer, but the idea stands. It could just be that it's a particularly hard maze for genetic mutation to find its way out of. Given enough time, it could. | ||
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mikado
Australia407 Posts
On November 30 2010 09:22 Half wrote: Hormones levels are also highly variable due to environmental influence....... But those influences are interpreted at a genetic level by threshold amounts again, set by genetic interactions. And that is not directly related to homosexuality, if you pump someone with testosterone or androgens, of course they'll exhibit opposite sex behaviour. Being 'born' gay however, is a difference in organ structure of individuals and/or their innate hormone levels. Exposure to gonadotrophins will only impede development, which is controlled by negative feedback systems. Once the stimulus is removed, the system will develop normally (fully functional males with women breasts due to hormone exposure, etc). But homosexuality is a complete switch of the perception of sex and sexual urges, there's nothing functionally wrong. | ||
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ZERG_RUSSIAN
10417 Posts
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MadVillain
United States402 Posts
On November 30 2010 09:26 mikado wrote: But those influences are interpreted at a genetic level by threshold amounts again, set by genetic interactions. And that is not directly related to homosexuality, if you pump someone with testosterone or androgens, of course they'll exhibit opposite sex behaviour. Being 'born' gay however, is a difference in organ structure of individuals and/or their innate hormone levels. But there is really no substantial evidence that people are "born gay." And that is what your entire argument seems to be based on. Its really too early I think to rule out factors other then genetics. | ||
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Sleight
2471 Posts
On November 30 2010 09:20 MadVillain wrote: Homosexuality is a maladaptive genetic mutation (as most mutations are) that has persisted in humanities gene pool through mechanisms similar to those found in any maladaptive genetic mutation i.e. genetic disease etc. Or, Homosexuality arises from environmental effects, possibly while the fetus is still in the womb. These effects could be physical, for example increased estrogen levels. Or they could be psychological, the absence of a major male influence during pre-pubescent life. I think its a combination of both, and any genetic factors are likely to be very subtle. Its silly to think that we'll someday isolate a "gay gene." Needless to say I really don't think there is remotely enough research to make any sound conclusions yet. Proof no one understands heritability. Most mutations which persist are NOT MALADAPTIVE. In fact, most novel genetic mutations dramatically compromise reproductive capacity and then the trait quickly dies off. Just because the mutation is very probable to occur (e.g. Down Syndrome) doesn't mean it is persistent. The people with DS do NOT reproduce, so the trait is constantly re-occurring. The only genetic negative traits passed down DO NOT AFFECT REPRODUCTIVE BEHAVIOR. Examples? High cholesterol, hypertension, Alzheimer's, type 2 diabetes, metabolic syndrome, etc etc etc. They all occur well after reproductive age is achieved, so evolution has NO pressure on them except through reproductive benefits/disadvantages. OR Environment? How does that explain homosexuality across multiple species and the entire globe? What mystery chemical keeps "turning people gay?" Psychological? Have you met any gay people? There is no evidence to support a "psychological" model of homosexuality that doesn't include sexual harassment, in which case, it is a side effect of PTSD, rather than the issue we are talking about. Seriously, people. Think with your brain. | ||
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Half
United States2554 Posts
On November 30 2010 09:26 mikado wrote: But those influences are interpreted at a genetic level by threshold amounts again, set by genetic interactions. And that is not directly related to homosexuality, if you pump someone with testosterone or androgens, of course they'll exhibit opposite sex behaviour. Being 'born' gay however, is a difference in organ structure of individuals and/or their innate hormone levels. Thats a stupid mentality. That's just chicken and egg. Then I could retort with something inane like genetics only adapted as a response to the enviroment, which would be equally valid according to your logic. Plus, you just conceded that genetics is not the sole influence, while how we react to environmental stressors is genetically predetermined, there existence and intensity is not Proof no one understands heritability. Most mutations which persist are NOT MALADAPTIVE. In fact, most novel genetic mutations dramatically compromise reproductive capacity and then the trait quickly dies off. Just because the mutation is very probable to occur (e.g. Down Syndrome) doesn't mean it is persistent. The people with DS do NOT reproduce, so the trait is constantly re-occurring. The only genetic negative traits passed down DO NOT AFFECT REPRODUCTIVE BEHAVIOR. Examples? High cholesterol, hypertension, Alzheimer's, type 2 diabetes, metabolic syndrome, etc etc etc. They all occur well after reproductive age is achieved, so evolution has NO pressure on them except through reproductive benefits/disadvantages. Hai guess what, genetic sterility is something that is present in almost every single species across the world. If there is a single gene that could cause homosexuality, then it isn't likely that it occurs at the rate it does relying on mostly maladaptive mutations. However, as I said previously, human sexuality is not binary (in fact the homo/straight thing is a really polar and stupid way to look at it), and if sexuality is influenced by a wider set of genes, then the role of maladaptive genetic defect could play a wider role. Environment? How does that explain homosexuality across multiple species and the entire globe? What mystery chemical keeps "turning people gay?" Psychological? Have you met any gay people? There is no evidence to support a "psychological" model of homosexuality that doesn't include sexual harassment, in which case, it is a side effect of PTSD, rather than the issue we are talking about. Environmental doesn't just mean social, it also means chemical, including prenatal hormonal exposure levels. Anything not directly deriving from genetics is enviromental. | ||
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_Darwin_
United States2374 Posts
On November 30 2010 09:26 mikado wrote: Being 'born' gay however, is a difference in organ structure of individuals and/or their innate hormone levels. Not if you are born in a womb. A mother's hormone levels have a huge impact on development... | ||
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mikado
Australia407 Posts
On November 30 2010 09:27 MadVillain wrote: But there is really no substantial evidence that people are "born gay." And that is what your entire argument seems to be based on. Its really too early I think to rule out factors other then genetics. Homosexuals aren't found in certain demographics or even species. Every species (almost) have it, regardless of the environmental exposure. And read my other posts and look at the citations I made. There are distinct differences in organ structure (larger hypotahalamus) and hormone levels (FSH, LH), if not on other metabolically significant pathways etc. | ||
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ZERG_RUSSIAN
10417 Posts
On November 30 2010 09:27 Sleight wrote: Environment? How does that explain homosexuality across multiple species and the entire globe? What mystery chemical keeps "turning people gay?" Psychological? Have you met any gay people? There is no evidence to support a "psychological" model of homosexuality that doesn't include sexual harassment, in which case, it is a side effect of PTSD, rather than the issue we are talking about. Seriously, people. Think with your brain. OH! You're totally right! There is no way that every HUMAN culture across the world could have an environmental influence on homosexual tendencies so obviously it must be genetic! | ||
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mikado
Australia407 Posts
On November 30 2010 09:29 Half wrote: Thats a stupid mentality. That's just chicken and egg. Then I could retort with something inane like genetics only adapted as a response to the enviroment, which would be equally valid according to your logic. Plus, you just conceded that genetics is not the sole influence, while how we react to environmental stressors is genetically predetermined, there existence and intensity is not. The existence/intensity of the environmental stressors are genetic if you're referring to the hormonal influence of the mother, as I was. As I said, once the baby is born, all the hormonal influence will do is impede development; not change psychological perception or urge. | ||
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MadVillain
United States402 Posts
On November 30 2010 09:27 Sleight wrote: Proof no one understands heritability. Most mutations which persist are NOT MALADAPTIVE. In fact, most novel genetic mutations dramatically compromise reproductive capacity and then the trait quickly dies off. Just because the mutation is very probable to occur (e.g. Down Syndrome) doesn't mean it is persistent. The people with DS do NOT reproduce, so the trait is constantly re-occurring. The only genetic negative traits passed down DO NOT AFFECT REPRODUCTIVE BEHAVIOR. Examples? High cholesterol, hypertension, Alzheimer's, type 2 diabetes, metabolic syndrome, etc etc etc. They all occur well after reproductive age is achieved, so evolution has NO pressure on them except through reproductive benefits/disadvantages. OR Environment? How does that explain homosexuality across multiple species and the entire globe? What mystery chemical keeps "turning people gay?" Psychological? Have you met any gay people? There is no evidence to support a "psychological" model of homosexuality that doesn't include sexual harassment, in which case, it is a side effect of PTSD, rather than the issue we are talking about. Seriously, people. Think with your brain. Ok I sense some major anger. I'll admit, biology isn't my area of science but I think you're misunderstanding what I'm saying. I'm saying that there could be some genetic trait that is being passed on, I dunno what the correct term would be for a non-adaptive trait that is passed on, yet is not maladaptive. I guess that was the wrong word. And by "enviornmental" I meant factors that aren't strictly genetic, i.e. hormone levels during development of a fetus, or yes even psychological effects. I think your gettings scared off by the word psychological, I'm not saying that its damaging or anything, but that being gay could have a basis in some difference in brain structure or function. I don't see how you're getting so angry. Do you think i'm homophobic or something? Yes I've met and have gay friends so chill out. Edit: @ Mikado, despite physical differences and the fact that homosexuality is seen across species doesn't necessarily rule out post-birth influences entirely. I still think that the research isn't really focused enough/ there isn't enough of it too make conclusions yet. Since this are big conclusions were all trying to make. | ||
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Half
United States2554 Posts
On November 30 2010 09:32 mikado wrote: Homosexuals aren't found in certain demographics or even species. Every species (almost) have it, regardless of the environmental exposure. And read my other posts and look at the citations I made. There are distinct differences in organ structure (larger hypotahalamus) and hormone levels (FSH, LH), if not on other metabolically significant pathways etc. Once again chicken or the egg. Prolonged Hormone use also caused physical changes in the brain too. I can't help but feel that this discussion is being artificially driven towards one direction because some people feel that homosexuality needs to be proven as 100% genetic in order to be socially accepted. While noble, that isn't good science. | ||
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Deletrious
United States458 Posts
On November 30 2010 09:33 ZERG_RUSSIAN wrote: OH! You're totally right! There is no way that every HUMAN culture across the world could have an environmental influence on homosexual tendencies so obviously it must be genetic! Sarcasm fail, lol. Okay, so according to you every culture in the world, and every environment of every species that also displays homosexuality, share an environmental influence in common that causes homosexuality. What an amazing coincidence, I am surprised no one noticed. | ||
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