Let me break this down for you

Apparently I only feel the need to write blog posts on the subject of homosexual rights/marriage... I swear I think about other things. Just yesterday I was imagining what it would be like to be in the middle ages with the knowledge and technology of today, because it would be awesome. I've been spending a lot of time trying to figure out how to house thousands of refugees in homes which are comfortable, durable, and desalinate sea water using the sun, because I care about shit like that. But this is about the gays. Some guy sent me a message on facebook, because he noticed I'd been posting about this whole homosexuality thing, and felt he needed to set me straight about how homosexuality actually isn't "natural" to which I felt

"
You throw a stone of an argument about how homosexuality is "unnatural" I won't stop at breaking it down to pebbles by pointing out the many species IN NATURE that exhibit it, no I'll pull out every genetic, biological, evolutionary, sociological, and just plain logical weapon in my thoroughly overcrowded arsenal and break that shit down to CLAY, and then mold it into a sculpture of your blighted understanding and cram it up through your overly tight sphincter until it lodges in your lymph nodes in the hope that it can serve to filter your inane vitriol before it spreads too far and pollutes the progressive air this country is finally starting to breath you ass backwards, high school genetics toting, pseudo-logical, fallacy spewing half-wit.
" 

And so I did. Here's his part of the conversation. And yeah, I'm including his name because fuck him.

Jeremy Dueck

Jeff, I noticed you writing a LOT about homosexuality---you seem to have a lot of time on your hands... I don't have a lot of time so this will be short and we'll take religion out of the argument for once. Do us all a favor, and stop telling people that you know homosexuality is natural when you have no evidence either. Physically speaking the acts of gay men and women go against nature. Take all the gay people of the world and put them on an island... no outside contact... they will all be gone in one generation. Mother nature doesn't even accept homosexuality. Its true and there is no good argument against that. Some studies in pedophiles also suggest a difference in brain function... but it doesn't make it right. Now if you want to go further you can talk about genetics. If even 80% of the people were gay at one point thousands of years ago, they would pass on genetic traits that would end with each truly gay couple right? Just like blue eyes get passed along because being gay is a physical trait right? Two parents pass on specific traits but if both gay parents don't pass along any genes (or even if SOME have kids heterosexually and pass along some genes), you have a diminishing level of homosexual genetics. Oh and since homosexuality rises and falls with different nations prosperity levels... don't let that sway you either. The reality is this, you are trying to be fair, and courteous to others, I understand this. But its a weak viewpoint and you're wrong when you use common sense and reason.

And my, considerably longer (sorry Time Crunch Jeremy, but while vitriolic nothing speech can be whipped of in 144 characters, straightening out your bullshit with actual facts takes a bit more time) retort.

I'll take this point by point.
Natural=exists in nature
homosexuality does. Many animals exhibit it to various degrees (exclusive throughout life and circumstances, dependent upon age, open to either sex, so on an so forth)
If you put a bunch of sterile/infertile people on an island, or a bunch of asexual people, or a bunch of truly devout catholic priests and nuns, all will be gone within a generation, these people are not considered unnatural, or immoral, or icky
In fact, I'd bet that if you put a bunch of gay and lesbian people on an island, barring the effects of starvation, thirst, disease, insects, and lord of the flies style internal warfare, they would breed and continue and it... Would .... BE.......... FABULOUS!!!!!!!!
because here's the thing, homosexuality falls on a spectrum, or rather, marks one end of a spectrum (though in reality it's not just a bar, but we can simplify it to that for the purposes of this conversation) with heterosexuality falling at the other end. People fall at various points along this spectrum, typically however only those at the very gay end identify as gay, and people in the middle rarely identify as bi, because there is so much pressure to fall into the "traditional" sexual identity, so if you CAN be attracted to the other sex, you tend to identify as heterosexual. However many studies have shown that heterosexuals of both sexes often have homosexual encounters, fantasies, and desires. The point of all this is that on your hypothetical island you would have some people who were attracted to some of the opposite sex members, and then you'd have people who are just willing to have a slightly awkward foursome in order to have children because yes, just like straight people, some gay people have the urge to raise children, and just like straight people, sometimes they do an excellent job, sometimes not. Please change your thinking to include a non binary sexual identity. I personally identify as straight, yet I have had crushes on men, and have seriously considered acting on them, yet most of my crushes, and all of my experiences have been with women. I am a living breathing example of the non-binary nature of sexuality. I'd bet even you have felt attracted to men before, though I very much doubt you'd even be able to consciously recognize the feelings.
Ah yes, the "gays are like pedophiles" argument. Guess what, pedophiles are natural too, and some at least or biologically created. What they do is immoral by the application of most any ethical philosophy. Their actions cause harm to others, they infringe upon the rights of children. They are raping, because a child cannot give consent, we have chosen to set limits on how old you have to be to give consent for many contracts, because we recognize that underdeveloped brains can't make fully rational and fair judgements, and that there are inherent power disparities between nearly all adults and nearly all children. None of that exists with (legal) homosexual acts. The participants are willing, adult, fully cognitive individuals who are unlikely to experience any damage physical or psychological due to the act (assuming it's done safely, just like hetero-sex). So there's that licked.
Oh yes, and genetics. My parents both had blue eyes, I've got hazel eyes, according to the simplistic model many of us learned in school at some point this means my mom cheated, because two blue eyed people (blue eyes being regressive) must produce a blue eyed child. Of course, eye color is effected by several genes, and possibly other factors, so we get much more complex genetics. Homosexuality is biological, it is PROBABLY partly genetic as well. The difference is that biological means that there are identifiable differences at the physical level, different hormone levels, different finger lengths, other little markers. These could be related to genetics, yet they are almost certainly effected by the intra-uterine environment. The chemical cocktail a mother feeds to her fetus effects the biology of the child. The more older brothers you have, the more likely you are to have homosexual impulses (if you're male). This has been shown with several studies, and it is suggested that this is an evolutionary mechanism meant to limit conflict between brothers in tribal societies where an overabundance of unattached men had the severe downside of murder and civil war. Evidence of a partial genetic cause of homosexuality is based on studying identical twins vs fraternal twins, with the assumption that apart from the genetic difference, fraternal twins and identical twins would have the same shared experiences both in the womb and in their lives. Identical twins are more likely to share their twins sexual preference than fraternal, but from what I've read this is still a somewhat unclear relationship. The point is that genes are complex, they can float around for generation and then come together in some novel way to throw up someone who looks like no one else in the family except for an old engraving of someones great great grandfather, who he resembles near precisely. Don't assume you can make some simple gay+gay=gay, straight+straight=straight comparison, it's far FAR more complex than that, partly because there are many different factors ranging from genetics to BAC which can effect someones sexual identity, and partly because sexual identity is both a gradient, and fluid throughout life (it is statistically possible for a guy who has always been straight, in every way, at all times, never a single thought of men, to meet a guy who he ultimately falls in love with. That guy might be the only many in the entire world who the first guy is "gay" for, but there it is. That could happen, it's just unlikely.)
I doubt homosexuality rises or falls with a nations prosperity. I suspect openness about homosexuality rises and falls with a nations prosperity. This is because as nations get wealthier they get less dogmatic and more accepting of difference. There's good reason for this, in times of scarcity we look to our "tribes" the group of people we most closely associate with, and consider all others to be outsiders who are liable to be trying to take advantage of us, that IS genetic. As scarcity falls so too does suspicion, and we come to accept those who are different. Also the kind of society that accepts homosexuals tends to attract creative types who, these days especially, drive economies forward, increasing prosperity. That's why having homosexuals move to town is really really good for that town. Look it up, that's economics.
I am trying to be fair, actually no, I am being fair, and I'm also being logical, and reasonable, and sensible. I'm also being accepting, understanding, considerate, progressive, honest, ethical, and exceedingly thorough.
If you're still with me i'd like to point something out. You never made any argument that could be considered "moral"
To recap
-first you said it was unnatural (not a moral statement)
-then you talked about the ability to reproduce (not a moral statement)
-Then you compared homosexuality to pedophilia, but only to point out that the same arguments for the "naturalness" of homosexuality could be made about pedophilia. This is called the association fallacy, which often can fool people into THINKING a moral claim has been made, when in fact only a factual claim has been made. Your factual claim was correct but it was (not a moral claim)
-Then you talked about genetics, which was mostly wrong, but also (not a moral claim)
-Then there was the odd comment about prosperity.
So maybe you AREN'T trying to make a moral argument. So what if homosexuality WERE unnatural? So's marriage (no other species marries, hell, even the "monogamous" species cheat like crazy), oh and cars, those are unnatural, charity beyond your immediate social circle, that's unnatural. Lots of things we do are unnatural, lots of things we know to be immoral ARE natural (rape, very natural, so's infantacide) so WHAT'S YOUR FUCKING POINT?