The answer is because when we are embryos in the womb, our basic structure (including the nipples) actually form before males and females branch off into different development stages. So if you like, we all grow nipples before its actually decided whether we are going to be males or females.
I don't actually know this answer but I'll try to help you. I know that the major gland for growth in males is located behind there nipple and disperses the major hormones for growth into adulthood which after growing is complete the gland will shrink as it uses up all the hormones and eventually goes away in a sense. I'm not a biology major though but thats what I was told once.
The short answer is efficiency of the genetic code. Rather than having to evolve two separate symbiotic species, the human race (and all our predecessors) evolved to use the same essential parts on both male and female. This is why male testicles (the analogues of female's ovaries) descend from a tract inside their stomach (which, on a female, becomes a vagina) into a small fold of skin- which, on men, fuses together at the bottom to becomes the scrotum, but on women form the interior vaginal lips. The clitoris on the female is the penis on the male- the difference between the two is, at least at the start, an effect of testosterone.
and so, you can probably guess, rather than making two types of boobies, the darwinian laws allowed us to share the same type but have them respond differently to the hormones in both bodies. What this means is that if you remove the relevant growth hormones (such as those found in birth control) from women, they'll look like men, or at least will stop developing- and if you give them to men, men grow breasts.
Maybe as a pacifier if mama had to go out and drag home a woolly mammoth.
Just kidding! Probably a programming error.
To pinch! Lol just kidding, don't know
I'm not sure exactly why, but it's an evolutionary thing with all male mammals.
So that men would not be so jealous of women.
They have nipples so I can pierce them lol. One more thing for a girl to tug on.. I don't know.
Cause,man are born by women...
Because boys have nipples girls have breasts.
Hard question but they do look weird without `em! Lol! =)
It can only be explained by genetics.
So girls can play with them while the guys play with hers! It's only fair! Right? I have rings in mine and I love it when a girl sucks on them!
It is the human body it works in weird ways and the way god made us can you just sit there and think what a man would look like if they had none