Absence of proof from an infinite pool of choices isn't proof of absence, but complete understanding of the genome would eliminate it by exhaustion. In terms o

Absence of proof from an infinite pool of choices isn't proof of absence, but complete understanding of the genome would eliminate it by exhaustion. In terms of XY exclusively-gay, I think epigenetic is still the leading hypothesis and not genetic by itself. It would be interesting to learn how the genetics set-us up for epigenetic influences. Other non-heterosexual and flexible sexualities for XX and XY seem more fluid and complicated to unpack. For example, I am unsure what proportion of lesbians are gold star and cannot be aroused at all by males, but I suspect it is low.