Because they don’t listen to Kathy Griffin?
So you’re saying that gay people eat babies?
Shyeah, right, and now you’re going to try to make out they don’t? 
Again, we can ask why the Japanese consider as a delicacy a fish that can cause you to die horribly and in spite of the best efforts of medical science, but no-one would think to ask why anyone would eat something nutritious and salubrious… would they? Or even why gourmet food, even when eaten for pleasure and not to ease hunger, would generally start out as something edible?
Evolution doesn’t have intentions; it just happens. (Unless you are arguing in favor of intelligent design, which is another thread.)
It doesn’t really matter what people intended for almost all of human history when they had sex - what matters is that those with heterosexual tendencies reproduced themselves at higher rates than those that happened to be attracted to objects with which they could not reproduce.
It’s the same reason that there aren’t a lot of folks out there who are sexually attracted to sheep, or trees. Maybe I am really just expressing my life-long devotion to that slutty elm trollop. Unless I can figure out a way to produce a fertile hybrid, my particular genotype is not going to recur.
It could be a common mutation, or an artifact of my species’ reproductive system. But it isn’t going to be selected for with anything like the pressure that exists if I am hot for Ooga, who can raise three of my offspring to the point where I can have grandchildren.
Regards,
Shodan
Sex is used for non-reproductive purpose throughout the animal kingdom all the time. Often, sexual acts (or acts related to them) are used to establish or reinforce a dominance hierarchy or to cement social bonds. But that doesn’t make the animals which perform those acts homosexual (in the human sense).
We humans derive our sexual behavior from our evolutionary past. Sex is fun and pleasurable for a reason-- the more you have sex, the more likely you’re going to pass on your genes. So, yes, having sex is all about reproduction (whether you want to have kids or not). Just because we humans have evolved brains big enough to understand the reproductive process doesn’t mean that our sexual desire isn’t rooted in the same biological processes as our less enlightened relatives in the animal kingdom.
I read somewhere the Greeks thought in the beginning there was only one kind of person, but something happened that cut them in two, right down the middle, wham, probably lightening. Ever since then the two halves have been running at each other trying to get back together.
It was either the Greeks, or John Cameron Mitchell.
The Greeks got a lot of things right, but this clearly is not one of them. I hope you mean this as a funny anecdote and not something that actually sheds light on the issue of sexual attraction.
I think the OP is going a little overboard, but I can see something to what he’s saying. When people talk about homosexuality, it is nearly always about the individual person. What is wrong with them or what made THEM that way?
When we talk of heterosexuality, it’s just brushed off as evolution/god made people that way. (depending on your viewpoint) I’m having trouble expressing exactly what I’m trying to say here. Bah!
Not quite. This leads to two types of gametes, and sexual species almost invariably have two types of gametes, isogamy (where there’s only one type of gamete) is extremely rare.
But it is very common for one individual to be able to produce both types of gametes, almost all plants that reproduce sexually are able to produce both types, although there are some exceptions…the kiwi fruit is one, a kiwi vine will either produce male flowers or female flowers, but never both. But single gendered plants are rare.
Single gendered animals are common though, which is something of a puzzle, since it’s not obvious what advatage there is in only producing one type of gamete. Note that lots of species simply shed gametes into the water or the air, so it’s not obvious why they shouldn’t produce both, they don’t need specialized organs for gestating embryos like mammals, they don’t even have internal fertilization. One plausible reason is simply to avoid selfing, where one of your sperm fertilizes one of your own eggs. If you only produce one type of gamete there’s no way this can happen. But plants have some interesting adaptations…some plants have closed flowers so that selfing is obligate. Others have biological mechanisms that recognize self pollen and prevent it from fertillization. Others just have flowers constructed in such a way that self-fertillization isn’t very likely.
So while there are ways to prevent selfing besides producing only one type of gamete, that’s the simplest way, but there are still plenty of hermaphroditic animals, and selfing isn’t universally disfavored either. You can joke about marrying your sister, but there are animals that are capable of successfully mating with themselves.
Anyway, the point is that sexuality and the evolutionary history of sexuality is a lot more complex than most people realize, and human sexuality isn’t a law of nature, it’s merely one particular solution of one particular species.
And then when we get into human sexuality it particular, we find that humans have a pretty odd social structure for mammals. The most striking is the complete lack of a mating season, coupled with long-term pairing (common in birds, very uncommon in mammals). If we were typical mammals we’d have a social structure and mating behavior similar to the gorilla.
I think it’s like everyone said above, that it’s not obviously adaptive. Why do people eat? Because people that don’t eat don’t pass on their genes! Why do people care for their young (mostly)? Because people who don’t care for their young don’t pass on their genes! Why do people have sex with the opposite gender? Well, you get my point.
Likewise, people tend to not understand people who don’t eat, people who don’t care for their children, and people who don’t have sex with the opposite gender.
There’s nothing wrong with homosexuality, but I don’t see how you can argue that it’s adaptive from an evolutionary perspective, or that it’s a trait that is likely to be selected. And if you think about natural selection for even a minute, I don’t see why you would ask about the origins of heterosexuality.
But there’s a valid question there. It’s obvious why males should want to have sex with females and vice versa, but it’s not obvious by what mechanisms this occurs.
What structures and pathways in a typical male brain makes him look at a woman and want to fuck her? How exactly does that work? Sure, we understand that a male elk wants to fuck a female elk, but what is it that makes that male elk have that behavior? Smells? Sights? Sounds? Why is it that one guy looks at a naked female titty and gets a boner, and the other yawns? Sure, one’s straight and the other is gay, but what the hell does that mean, deep down in the nervous system?
It’s an interesting question, but the trouble is that we understand so little about how the brain works that we can’t even begin to answer the question.
I’m not disagreeing with you. As I said, I’ve having trouble expressing exactly what I want to say.
It seems to me that most of the time we don’t understand something about evolution’s “purpose” in a feature or behavior, it turns out that the feature of behavior in question is a consequence of some system or process we either are unaware of or have not considered.
Men have nipples not because thay have any use for men but because women need them, and men and women come from a long complicated development process, leaving men with relic nipples.
Hetero sex might be used infrequently for procreation, but that probably doesn’t mean that it’s intended for something else…it probably means that we’ve put it to other uses, social and physical, after we developed it.
I suspect we will eventually figure out some reason why homosexual behaviors are adaptive…perhaps to a group (superorganism), if not to the individuals themselves.
Sailboat
Huh? Why a gorilla? They have a harem type of social structure and that’s typical of mammals with significant sexual dimorphism. Humans are more like chimps in our degree of sexual dimorphism (no shocker, there), so why wouldn’t our making behavior be more like chimps (or bonobos) if we were typical? And how do you define “typical”?
A trait doesn’t need to be adaptive to be present in a population. As **Colbri **has mentioned in similar threads, the occurrence of homosexuality in humans is about on par with the occurrence of infertility. No one asks why infertility is adaptive, do they?
“Why are so many people heterosexual” can be seen as 2 different questions: First, one can look at the question from an evolutionary perspective. Second, one can look at the question from a physical/psychological perspective.
The first question is pretty much a no-brainer. The second is more interesting.
The same 2 questions can be asked about homosexuality. However, both of them are interesting questions.
But that’s the other way around…sexual dimorphism is a consequence of having a harem type social structure.
And when I say “typical” that just means I can come up with dozens of examples of mammal species that live in multiple female-single adult male social groups. That’s a very common sort of social structure for mammals, following from internal fertillization and internal gestation. Or at least, animals that form such a social structure during mating season, and then when mating season ends the alpha males leave.
In addition to what is proposed here, I would add it is of a spiritual nature:
Kindly go away. Suggesting that someone is gay because they are possessed by demons is not at all productive to this discussion.