This might seem a bit weird, but why can only women produce milk? Wouldn't it be more beneficial to our species if all humans could produce it? I can't think of any reason only one gender would need it, unless it would somehow be harmful to men.
I know that men can secrete milk in some cases, but why not in general?
beneficial to our speciesvery much suggests that you misunderstand evolutionary processes. – Remi.b Dec 28 '15 at 18:40