New Gay Origin Theory Proposed

Scientists May Have Finally Unlocked Puzzle of Why People Are Gay

A group of scientists suggested Tuesday that homosexuals get that trait from their opposite-sex parents: A lesbian will almost always get the trait from her father, while a gay man will get the trait from his mother.

It's long been observed that homosexuality has a genetic component, but a weaker one than seemed likely through direct inheritance of a genetic trait.

Long thought to have some sort of hereditary link, a group of scientists suggested Tuesday that homosexuality is linked to epi-marks — extra layers of information that control how certain genes are expressed. These epi-marks are usually, but not always, "erased" between generations. In homosexuals, these epi-marks aren't erased — they're passed from father-to-daughter or mother-to-son, explains William Rice, an evolutionary biologist at the University of California Santa Barbara and lead author of the study.

Epi marks are modification of DNA, the material of inheritance after reproduction, sometimes in response to environmental condition, in this case, the hormonal environment of the womb. Shades of Lamarkian evolution...

"There is compelling evidence that epi-marks contribute to both the similarity and dissimilarity of family members, and can therefore feasibly contribute to the observed familial inheritance of homosexuality and its low concordance between [identical] twins," Rice notes.

Rice and his team created a mathematical model that explains why homosexuality is passed through epi-marks, not genetics. Evolutionarily speaking, if homosexuality was solely a genetic trait, scientists would expect the trait to eventually disappear because homosexuals wouldn't be expected to reproduce. But because these epi-marks provide an evolutionary advantage for the parents of homosexuals: They protect fathers of homosexuals from underexposure to testosterone and mothers of homosexuals from overexposure to testosterone while they are in gestation.

So, in a sense, this model, if proved true, would foist the blame for cause of being gay at least back two generations, first to the grandmother whose hormones caused the parents genes to be modified, and then, to the opposite sex parents, whose reproduction failed to "clear" the epi marks during reproduction.

It explains the weak inheritance observed in homosexuals, and it will be a popular theory in the PC world in that it still leaves the cause external to the homosexual, who can still say they got it from their "epi-genes", and thus should not be grounds for discrimination, although it does come uncomfortably close to being a genetic defect.

Remember, though, it's just a theory, a neat theory, but one without a shred of evidence at this point. I'll go 50:50 at this point.