So Much for Intelligent Design

Why do men have breasts and nipples?

...[B]ecause they already had them before they became male.

But then why didn't evolution opt to remove those seemingly useless female parts?

Because evolution doesn’t simply wipe out unnecessary physical bits and pieces. Those parts have to be a burden, or be in the way of survival and reproduction for evolution to take notice. Since there's no real caloric cost to men having boobs, evolution has no impetus to erase them.

In fact, men's breasts are a good lesson in the higgledy-piggledy way that evolution works. Natural selection chooses for and against body parts, but there is no master plan that aims for the perfect creature. Men have boobs, women get facial hair, and we all stand in front of the mirror asking, "Why?"

Maybe men have boobs so they can get to wear the man-bra. So much for intelligent design.