molbiogirl writes:
It seems they found a "genderblind" (GB) mutation. Males carrying GB were attracted to males; females, females.
"Genderblind" means the flies were bi-sexual, and would attempt to mate with both sexes indiscriminately.
This may not have much to do with human sexuality, because, whether heterosexual, homosexual or bi-sexual, we are never literally gender blind, and seem to have enormous variety of tastes within those three categories.
I'm probably stating the obvious, but I think that human sexuality will turn out to be much more complex than that of the flies, and will involve complex combinations of genes and other factors.
As for the "gay is a choice" thing, we don't actually need biology to know that that's not true, because we all know from experience that we don't choose our sexuality.
Interestingly, the people pushing the "gay is a choice" idea must, by definition, be either consciously bi-sexual, or consciously gay and pretending to be straight.
No heterosexual would regard being or not being homosexual as a choice they've ever made, obviously.