Sure it does. We're a sexually dimorphic species that can only reproduce with one XY and one XX.
Differentiating between them is vital to the continued existence of the species.
Talking with your buddies of the same gender about how you were hanging out alone with one of the opposite was a tribally significant thing in the early days of speech. It still today implies you might be mating! And babies might be forthcoming.
Differentiating between them is vital to the continued existence of the species.
Talking with your buddies of the same gender about how you were hanging out alone with one of the opposite was a tribally significant thing in the early days of speech. It still today implies you might be mating! And babies might be forthcoming.