A cartoon by Carolita Johnson in the New Yorker of Jan. 16, 2017 shows a young mother dressing while her little daughter asks, "Mommy, when will I blossom into a beautiful projection of male desire?" Sex, at least among mammalian species, is an odd deal. For some, it means little. An occasional meeting somewhere in the forest, perhaps never to meet again. I have no idea what the fertility rate among bears, deer, or wolves is, but I do know that humans have gone out of their way to engage in sex without pregnancy. Still, reproduction or not, bodies, voices, gestures and social mores such as typical personality traits underline and emphasize our genders all day long.
As one ages and gets a chance to more or less view life in its entirety, male desire, and I guess female desire, show themselves to include many ideas and projections, concepts and standards and expectations that are a bit vague, a bit unreliable, maybe a bit unsteady. When you think of young people being entranced by the whole business of attraction and starting a long relationship, it seems unlikely that the lovely skin and zest and brightness can wrinkle and fade without removing the fun and connections between people but it does happen. Even older people who by fate or choice or both are not paired are affected by the biological markers of sex. Watch 80 year olds and you will see many of the same instant adjustments to the sex of others that you can see among 20 year olds.
Nobody wants to suffer or lose or be restrained just because of the gender accident of birth but our awareness and our projections from Mommy and Daddy, from our siblings, from grade school and high school and movies and stories and dreams and hopes and aversions have strong sexual colors in them right along. Our marketing and our genetics are likely to keep things that way for a long time.