When gay people come out of the closet, they usually run into some variation of the “but that’s unnatural” argument. This is the apparently sensible claim that it doesn’t make sense to be gay. Isn’t sex for procreation? Why would two males or two females become romantically involved if they can’t have a child together?
It seems like a reasonable argument. You can point out that some sort of gay behavior occurs in every species in the animal kingdom – which is true – or that gay sex is simply fun – also true. But that only begs the question. Why? Why are there so many gay animals, and people, in the world when reproducing your own kind is the basis for a species’ success? Having fun doesn’t seem to explain this apparent contradiction.
The answer is that gay people help nature hedge its bets. A successful species typically keeps extra cards up its sleeve because the rules of the game can change without warning. Gay people represent some important extra cards. They are a natural, genetic variation that helps guarantee the successful raising of young.
Many species show wide genetic variation. Dogs, for example. 
You can breed a chihuahua that weighs 2 pounds. Or you can breed an Old English Mastiff that weighs 300 pounds.
Why should canine genetic material be so mutable? Because being tiny – or being huge – might come in handy. You never know.
The ultimate disaster for a species – extinction – happens when its members fail to adapt to an altered environment. That’s why you want to have as much flexibility as possible to respond and survive when something unexpected occurs.
It could be a meteor striking the Earth. Or a volcano erupting. Or a pandemic disease wiping out three-quarters of the population. The game can change – and a species has to change too – sometimes a lot – in challenging new circumstances.
Having gay members of your species could make the difference between survival and extinction. Gays are unique – and vitally important -because they do something no other members of that species will do.
I don’t mean have gay sex.
I mean raise other people’s children.
Gay animals are perfectly happy to pair-bond and mate with members of their own sex, so their sexual relations are non-procreative. They do not have children with their partner. That means they are available to raise another animal’s children.
Say a heterosexual zebra, or otter, or muskrat or human is killed and leaves behind a helpless child. Heterosexual animals, who can have children of their own, will probably refuse to raise this other animal’s child, or at best do so grudgingly. They have their own children, who are a higher priority because they will pass on their genetic material. But a gay member of the species will happily step in and raise that helpless child.
He has no reason not to. He is not caught up in the battle to mate and reproduce. His preoccupation is caring and nurturing within a relationship.
If a male animal loses a female partner and is left with children who need care, he might have trouble locating another female willing to raise these children. But a gay male would happily accept the job.
If a female animal loses her male partner and is left with young to raise, another male might reject the task of raising those children. But a gay female would, similarly, be happy to help out.
Gays play a role in increasing the success rates for child-rearing in all species. In the event of a large-scale disaster, resulting in many adult deaths, gays could fill an especially vital role in helping to raise the young. They would not compete for sexual partners. But they would help out with the kids.
It could make the difference to a species’ survival.
That’s what’s happening right now, with humans.
Many heterosexual human couples have children they are unable or unwilling to raise. These children are put up for adoption – but there are too many of them to be cared for solely by heterosexual volunteers, who usually prefer to raise their own children.
That’s why, throughout the world, gays are the unofficial backbone of the adoption system. Without them, many children would suffer terribly, never finding wiling, dedicated adoptive parents.
It is an open secret that in most states, the adoption system would collapse without the participation of gays and lesbians. In 2007 it was estimated that there are 270,000 children living with same-sex couples in the USA. Of these, one-quarter, or 65,000, have been adopted. Gays are a small minority, perhaps as few as 4% of the general population. But there is no question that gay people do a lot of adopting and provide loving homes for hundreds of thousands of children who desperately need them.
Unfortunately, in a few states, right-wing religious zealots have persuaded politicians to ban gay adoption. It is not clear whether this misguided attack on children and the rights of gay people is constitutional. A court battle is raging in Florida.
Meanwhile, these laws prevent gay people from playing a role nearly as ancient as life itself. That is a tragedy, which could result in a calamity.
It’s also unnatural.
Prince William, for his part, might choose to marry someone like Princess Diana, or he might not. His mother may well have been a lovely, giving person and the perfect model for a mate.
The People's Therapist 