And the Bottom-Line, No-Bullshit Fact About the Significance of Sexual Dimorphism in Humans Is:

that being 30% bigger and stronger than women gives men evolutionary license to rape them, and/or, if it comes to that, gangbang them.  Not that I ever would, or that I think it's a good idea; but that is what sexual dimorphism means for other animals--Why should we be different?  And not only that (now that we've got the ladies at a fever pitch, and just to bring 'em to a boil):

Sexual dimorphism (difference in size and suppleness) is probably what makes the sexual connection between full-grown men and half-grown boys so common, and delightful, a normative factor in human society throughout the history of our species.   And it also explains why both the earliest forms of heterosexual marriage and homosexual paedophilia  (such as that practiced in ancient Crete--and of course epitomized in the myth of Zeus and Ganymede) always contain a large element of more or less ritualized Abduction, which seems to serve the dual purpose of making the new relationship both official and juicy hot.