Gay men i understand; lesbians dont make sense to me from an evolutionary standpoint.
Is the butch dyke that way because she is partially infertile? can she get pregnant if shes raped?
They make exactly the same sense as gay men from an evolutionary standpoint: either a developmental mistake from getting the wrong signals in the womb, or possibly a way to produce non-reproductive animals that can assist the overall population's fitness in various ways.
Lesbians don't exist. Female sexuality is psychological and fluid.