For decades, I have occasionally puzzled over the dichotomy posed, in the evolutionary context, by homosexual persistence.  As we all learn in high school biology, if the male peacocks with the most spectacular plumage are more successful in attracting female mates, then over time, the male progeny will develop even more spectacular plumage as the gene for this trait becomes more dominant.  Conversely, if the females spurn the advances of the male peacocks with puny tailfeather displays, then the genetic trait for puny plumage will gradually become less and less dominant (i.e., more recessive), even to the point of disappearing altogether.

So then, how is it that the human homosexual trait, with its associated reduction in reproductive rates (estimated to be about 22%), persist in the human gene pool?  An article from earlier this week by William Kremer in the BBC News Magazine was helpful in shedding some light on this puzzle.  An excerpt:

… Since the early 1990s, researchers have shown that homosexuality is more common in brothers and relatives on the same maternal line, and a genetic factor is taken to be the cause.  Also relevant – although in no way proof – is research identifying physical differences in the brains of adult straight and gay people, and a dizzying array of homosexual behaviour in animals.

But since gay and lesbian people have fewer children than straight people, a problem arises.

“This is a paradox from an evolutionary perspective,” says Paul Vasey from the University of Lethbridge in Canada.  “How can a trait like male homosexuality, which has a genetic component, persist over evolutionary time if the individuals that carry the genes associated with that trait are not reproducing?”

My question, exactly.  For more on what the latest research tends to reveal, read the whole thing, HERE.