[Exon Auxus]

Originally Posted by TitaniumAnimations

But if this gene is passed down through that way, where in the world was it first conceived, and when... and how? Since genes and hereditary traits are mainly compiled of natural adaptations to the surroundings of the living being, why would one develop such a trait?

They happen as a result of mutations. Like what Hoshika said, those who survive with a certain trait do so because of "natural selection". However homosexuality as an anomalous expression of genes isn't as drastic because you aren't going to die just for being gay. xP