Since the first comment didn't work, I'll try going into more detail.
Our genetic code doesn't include statements like "if (is_male) { try_to_have_sex_with_ladies(); } else { try_to_have_sex_with_dudes(); }".
Our genetic code produces proteins of different shapes and those shapes influence the development of the structure of our brains and their function and that brain generates feels of various kinds that lead to attractions of various kinds.
Evolution works by changing the coding of the genetic code which changes the shapes or amounts of proteins produced which changes the development... a local maximum happens when the final system produced (our feels of attraction) would be negatively affected by any individual mutation on the genetic code. There may be better feels-of-attraction systems you could build from scratch that would propagate the species better than ours, but you can't turn ours into this better system without making it worse for awhile.
Nature can't make arbitrary changes; it can only make incremental changes. And consequently, we frequently get stuck at local maximums rather than global maximums.
Our genetic code doesn't include statements like "if (is_male) { try_to_have_sex_with_ladies(); } else { try_to_have_sex_with_dudes(); }".
Our genetic code produces proteins of different shapes and those shapes influence the development of the structure of our brains and their function and that brain generates feels of various kinds that lead to attractions of various kinds.
Evolution works by changing the coding of the genetic code which changes the shapes or amounts of proteins produced which changes the development... a local maximum happens when the final system produced (our feels of attraction) would be negatively affected by any individual mutation on the genetic code. There may be better feels-of-attraction systems you could build from scratch that would propagate the species better than ours, but you can't turn ours into this better system without making it worse for awhile.
Nature can't make arbitrary changes; it can only make incremental changes. And consequently, we frequently get stuck at local maximums rather than global maximums.