Okay. I'm interested in more than that. But receiving that book as a birthday gift made me think about other differences between men and women beyond the obvious ones.

In particular the difference in percent of body fat and water content of their bodies. Surprisingly there is not a lot of good data out there that I know about. Maybe some of you who study these things would know more.

It seems that any evolutionary reason that could be given could have an equally logical counter-arguement.

Oh yes. The reason men have nipples I think is that they develop before the Y chromosome kicks in in the developing embryo - just an artifact that evolution hasn't needed to clean up as far as I could determine from an internet search. And it makes sense. I'll see what Leyner and Goldberg have to say about it when I get to that part.

But the fat and water thingees still confuse me. The basic fact is that men have less fat and more water, and both seem a little differently distributed in the tissues of the body, depending on the study. Why has nature bothered? Is it a nipple-like artifact?

Some background: Body Composition, Health and Athlete Performance from USA swimming.

Why do men have nipples? What would I use my clamps for???

The body fat is because of pregnancy, it gives women a store to draw on during pregnancy and lactation. Remember, our bodies evolved when scarcity of food was the norm.
Male nipples are one more indication of the absurdity of "intelligent design", unless, of course, the ID'ers want to concede that men have them so they can be sexually stimulated.

What else would you pinch and suck on?