Gays and lesbians make perfect sense in an evolutionary sense. It's does crossover into other pack animals like wolves or gorillas too.Nobody is saying all the world is A or B? I don't look at it from a religious point of view; I look at it as we are a species like every other species; our general purpose is to eat and drink, pee and poop, have sex, and make babies. There's your A & B which is the majority of our species. Which, for the most part is the prime directive of all species on this planet. But when babies are made, some don't come out of the baby-making organ of pregnant people [were not allowed to call them women anymore] they don't always come out cookie-cutter to the majority.
Man, I can't count on two hands how many gay people I've met since I became active in the arts. I don't judge any of them. My bitch with this community is not how they feel or how they dress or identify. My problem starts when people say that I should feel a certain way about this, and if I disagree, I am a bigot. You can identify however you want, but biology says otherwise, so this is really a mental issue rather than a biological one. The same could be said of being gay. A & B are here to procreate, even if some deviate by mental state or by design. I don't judge people's sexual orientation because I don't care what people do in the privacy of their bedroom. My pushback is that a tiny minority is trying to completely undermine the construct of gender because of how they "feel." They aren't saying we are a new gender; they are saying they are one of the two genders, and well, they aren't; they just feel like they are. But wait! I just confused myself because a quick Google search revealed there are actually seven genders: agender, cisgender, genderfluid, genderqueer, intersex, gender nonconforming, and transgender. Disagreeing with that could get you arrested in some countries.
There are dominant pairs that breed and keep order and there are subordinates who don't breed but are doing their share in caring for the young, protection of territory and assisting the top dogs when hunting or off defending territory.
In our abundant world the extended family isn't necessary for survival but in other parts of the world where family is neccesity for survival there are no genders, just roles in a family.