According to classic liberal and evolutionary thought, if homosexuality was truly a genetic issue, it would have been eliminated from the gene pool a long time ago as it confers no benefit to the survival of the species. As I have always said, the logical consequence of homosexuality is the end of the human race in one generation. If it is good enough for a pathetic 1.5% of the population, it is good enough for everyone. Their twisted logic makes no sense. It is moral, not genetic.
Not necessarily. Many diseases are genetic in origin, but they persist because they exhibit a phenomenon known as “partial dominance,” and the partially dominant state confers some benefit so that “rather gay” men were more likely to breed than totally straight men. If a recessive gene is found in 10% of all men; it would only be fully expressed in 1% of men. The partially dominant trait would only have to increase successful reproduction by more than 10% to make up for the recessive trait absolutely preventing reproduction.
However, it’s pretty clear that homosexuality is largely non-genetic. Studies of twins show a very low correlation, whereas a purely genetic trait would show 100% correlation.