Wikipedia:Wikipedia commentary/Why we have sexuality

Much thought and research has gone into considering why some members of a species should prefer to mate with their own sex. It has been suggested many times that there must be a gene for homosexuality. This might be true and perhaps one-day research will provide the answer. Here is a different theory.

It is acknowledged that a male does not need to be choosy in which females he chooses to mate with. The important thing for a male is to spread his genes around and have as many offspring as possible. As one female can have only one offspring at a time, it pays a male to have sex with as many females as possible, there being little cost each time he does so, and the possibility of the reward of passing on his genes. This is well known. It is usually assumed that members of a species are bound to want to mate with the opposite sex because to do otherwise is a waste of reproductive effort. This commentary sets out to challenge that veiw and provide a basis for homosexuality.

Suppose a species existed where its members made no distinction between male and female. They would mate with whoever happened to be around at the time fitted whatever other criterion for choice had evolved in the species. Such a species would survive because, on average, 50% of sexual encounters would be with members of the opposite sex and so produce offspring. For the males in particular, there would be little cost in the wasted effort mating with another male for exactly the same reasons as there is little cost in mating with a female who does not then go on to have his offspring. Suppose then, in this species, a gene emerged for choosing the opposite sex over the same sex to mate with. Such a gene would spread, as members of the species carrying it would have the potential to mate successfully more than 50% of the time, in fact this would give the potential to mate successfully up to 100% of the time.

So now we have a species that has a gene not for homosexuality but one for heterosexuality. Such a gene would have to do two things. 1. Enable the distinction to be made between male and female. 2. Make its carrier choose the opposite sex. If the first part if this instruction failed to operate then the individual would make no distinction between male and female and would be bisexual. If the second part failed then the individual would distinguish male and female and go on to chose his or her own sex, and therefore be homosexual.

See also : Wikipedia commentary