Homosexuality as a genetic condition vs choice......?

Homosexuality can be an evolutionary advantage in providing extra caregivers for the children of one's relatives. Since the genes involved are 1/2 of one's own genetic load, this is roughly equivalent to passing on one's own genetic material.

Since it appears that the later a boy is born in a family birth order the higher the possibility that he will become homosexual, the "extra caregivers" hypothesis takes on a little more weight.

Also... it obviously has SOME utility, because it's seen across a wide variety of animal species, including human beings. The observed facts can't be disputed, even if their interpretation is being debated.

An article on the subject of homosexuality and natural selection:

http://www.newscientist.com/article/dn13674-evolut...

ETA: You're welcome. Glad you found the article interesting. :-)

Procreation is a relentless rule yes. However, even Mother Nature puts limitations on breeding to a point. Take the whitetail deer. If too many of them breed without being killed by hunters in some form (humans, wolves, bear) than the population as a whole will eventually suffer from starvation and disease due to the inability of the earth to sustain them all. I view homosexuality as a welcome (and natural) change in the human need to overpopulate and ravage it's host (the earth). Homosexuality leads to less accidental births which in turn leads to less of an overpopulation problem. I am not homosexual but I choose to not breed on the basis that there are already too many children who need good parents. If more (not all) heterosexual couples would make this choice we could make this a better planet to live on for the generations to come.

Homosexuality is an advantage to a species in this way. It helps to prevent possible suffering from overpopulation to the members of the next generation that would have existed (and will exist in smaller numbers) if homosexuality didn't exist.

On a purely individual basis, you're certainly right, assuming that homosexuals seldom produce children. I think that assumption is very suspect, but I'll leave that to you to consider. However, in terms family, tribe and clan, the incidence of homosexuals may actually positively impact the ability for the survival of the closely related gene types. In a number of cultures, gay individuals would not marry, but would instead stay with their close relatives and help to raise the next generation of nieces and nephews and cousins, thus providing additional adult support, and an additional set of working hands to support the children.

There are a number of other genetic factors involved, including studies which show that the mothers of homosexual males may have higher fertility rates, thus improving the chance of reproduction of the gene type. See below.

If the real purpose of Evolution is survivability as a species, wouldn't increasing population pressures lead to genetic mutation and change over time that allowed for alleviation of this pressure, thereby ensuring long-term species survivability?

Essentially, homosexuality may be an Evolutionary response to over-population and scarcity of resources. It may actually be an essential piece of our survival story.

Just a thought.

Homosexuality is neither genetic nor a conscious choice. No one is born homosexual, but no one wakes up one morning and decides to be gay either.

Homosexuality is a perversion of a person's sexual identity. Think of a pedophile. No one will ever claim a pedophile was "born that way". He probably started looking at some sort of pornography, and over time he had to find more extreme forms of pornography to get the same stimulation, until eventually he begins using children. He didn't go to sleep a healthy individual and wake up a pedophile.

It's similar with a homosexual. Homosexuals generally went though an event at an early age that confused their sexual development. It could have been as traumatic as being sexually molested(which happens a lot more often than you may think), or it could have been as simple as being picked on at school and only being accepted by the "gay crowd", and so that gradually becomes their sexual identity.

So in the end, no it isn't a genetic condition, and it isn't a choice either, it is a sexual perversion.

There's several possible evolutionary advantages to homosexuality.

One, since they are unable to have children, they are able to focus their lives on the arts, etc, and so be able to give us more in that way. Think of it like this. A doctor who has children is capable of being distracted and busy on an emergency driven night. A doctor without children (or even a relationship) would be an asset to the community and help the next generation survive. Sure, biologically they may not be 'fit' and have grandchildren. However, they are an asset to helping the community survive, and there's arguably evolutionary assets that we have for the 'community' over the individual since humans are more community oriented. Ie, lone humans surviving doesn't really happen. We function as a community, so sometimes humans are born that don't have an evolutionary function other than helping the community.

Second, a person unable to have children is capable of raising other people's children. Think wolves. You have main breeding pair, and then all the other wolves tend to help raise that main breeding pair's puppies. They are able to help their genes survive the next generation by helping the next generation of their family survive. The only problem with this is that, as far as I know, it's not that simple in the wild. Typically, wolves leave and go find a mate with time, they only do this babysitting gig while they're 'teens' until they're 2-4 years old. Another problem with this is that not all gays LIKE children, and not all gay men have inherited a 'mommy' type reaction to problems, nor do all lesbians show an instinctual or desire to be mothers.

Third, far more common in the wild is if a bachelor wants the ability to pass on his genes, he needs an edge. Pairing up with another bachelor, cementing bonds through sex, and then working as a team to rape or hold a female for breeding, or work as a team to kidnap the child/egg/etc to raise themselves. Dolphins, lions, some birds, some hooved animals, etc work like this. Does it happen in gay couples? I don't know. It's extremely hard to use animal behavior to justify human behavior (and shouldn't be done, but often is in discussions like this.) But it IS a visible evolutionary advantage we see in the wild.

Add: 2%, not 10%, are homosexual. Maybe as much as 7% if you include variations like bisexuality. And, oddly enough, this percentage does not seem to be increasing in the more populated cities, it seems pretty stable. So "it's a response to overpopulation" doesn't quite hold water.

People have chosen to be in a group that is hated and persecuted in the past. Being in a chosen 'small' group scenario increases the uniqueness of the individual and the feeling of being something more than those around you. It's happened all through history, small groups of people, even if they are all killed, forming in spite of the persecution. Holds no water to say "no one would choose that" when people have all through history.

The idea that hormones in the womb influence sexuality is very popular, but not very sound. It only accounts for about 17% of people with SSA, and makes absolutely no sense for things like lesbians, or when a male has all female sisters, or is first born, or younger siblings who aren't gay. Add into this that actually we have DONE the research about whether these hormones affect sexual orientation (and found they don't) and it's just not a sound theory. Popular, yes. "But what about older brother's effect?" Quite simply, this is more behavioral than genetic. Younger siblings have, through history, been observed to try and be as different from their older siblings as possible. It's confirmed birth order work, and has been around a long time.

Add: That's why I said they were POSSIBLE explanations. They're explanations I've heard people give as to evolutionary advantages, which is what she asked for.

Lions actually have had recorded sexual behavior, such as mounting. They're actually one of the most documented 'homosexual' animals, especially in their bachelor prides. Female lions also mount one another. The actual scientific rational isn't that they're sexually attracted to the same sex but that they are using sex as a bonding mechanism. And you can see sex used for bonding in a lot of different animals.

Historically, homosexuals have not always been outcasts. *shrugs* Check out "two-spirit" information from the Native Americans for instance. The fact is that someone who is homosexual and actually not having a relationship would have more energy to devote to the family/community. It's a possible evolutionary advantage then to have homosexuals in the community. That doesn't mean that it IS, but that it's possible. As for passing things on... if homosexuality occurs at a 2% rate in a community, that would mean that there would at some point be a progeny that they would pass on to. Knowledge being passed on in that case.

The third I admitted may not be applicable to humans. There are some possible scenarios where it COULD possibly work, but they stretch too far for my comfort. However, she didn't say "ONLY in humans" but was more broad in her question, and ignoring this evolutionary benefit would really downplay species like dolphins.

Disagree all you want. These are actual evolutionary arguments that have been used to 'prove' homosexuality can be a benefit to a community. And some of these arguments can be used to disprove 'homosexual behavior' in some animals. For instance, someone talked about female birds bonding to one another through sexual-bonding rituals in order to raise their eggs. They both had eggs, meaning they both had heterosexual sex, but the fact that they bond together to try and raise the eggs (only one survives) is enough for people to say "See! They're gay!" when their behavior isn't.

It may have evolved evolved because there were times when genetic disorders took the population of males or females too low, or it may simply be a "quirk" of evolution -- meaning that it has no selective purpose.

I think the most common view is that homosexuality occurs because of exposure to hormones in the womb, not because of genetic factors.

Kin altruism is one possible way it makes "sense" in evolution.

It's been well-documented in several other species besides humans.

Consider two parents who have 6 offspring, all males. In many species (including humans) not every male gets to procreate, especially in those species that have something like an "alpha male" herd, pack, or group structure -- in those kinds of groups, usually one or two males get to mate with one or more females, often after some show of superiority on the alpha male's part...while the rest of the males serve as helpers to the group but never procreate.

Given that out of a group of 6 brothers, only 1 or two are likely to ever procreate, how can the other 4 or 5 males help insure their genes continue to live on? Well, since the odds are good that any one brother shares at least 50% of his genes with any other brother, helping a brother to procreate means at least a large percentage of your own genes will get passed on.

There are lots of ways one brother can help another to procreate as much as possible: help care for the women and children that the other brother has, provide resources to the brother's family group (hunting, gathering, etc.). But one interesting way to consider helping: reduce the competition that other males (ones NOT a brother and so not sharing your genes) might give to your own brother for females. That could be done by fighting them off, or perhaps even by getting them to be sexually satisfied *without* mating with a female...if they're sexually satisfied without mating with a female, they're not going to compete with your brother for females. Your brother gets all the females, and most of your own genes go on to the next generation through him.

It's really not hard at all to think of ways that some homosexuality in groups could be beneficial in an evolutionary sense. There's one way above -- people have come up with dozens of others that are perfectly plausible.

In any case, does your acceptance of some human being and their basic rights depend on their evolutionary usefulness? Mine doesn't. That kind of attitude sounds a lot like eugenics...

Peace.

Edit: phrog, OK, just making sure -- on here you never know :)

interesting thoughts - some interesting answers

it is possible that it has a secondary effect on population advancement, as others have mentioned - but that raises the question of why not a lack of ability to reproduce in that case rather than an inclination toward behavior that is not conducive to reproduction.

very interesting. thank you.

Homosexuality does occur in nature in almost every animal species. I think that genetically it has derived more from hyper sexuality than anything else.

Most animals that exert homosexual behavior are bisexual and are more hyper sexual. This may mean that they they actually spread their seed to more mates because they are hyper sexual and are more likely to have more mates that are both female and male.