why do men have nipples?

Answer 1

because all little boys start out as little girls, in the womb. Later in the pregnancy, their genitals descend, they start producing testosterone, and their breasts generally go un-developed

Answer 2

What man has lactated? Show me a medical text on that topic! I want an exact referece cause I never heard of it!

According to accepted medical fact, all humans are created female and at the 7th week males change, apparently the nipples do not vanish, they simply do not develop as they do in females, just like the penus doesn't vanish it simply becomes the clitorus, however the urethra moves from the clit to above it.

All we can say is this seems to be the "nature" of things.

The X chromosone simply doesn't negate the nipples, it siimply relgates them to duncil (dunsil) status.

Answer 3

All human fetuses start out as female. In male fetuses, testosterone will kick in at a critical time in development and the male characteristics will form. The nipples (and even breast tissue) have formed up to a certain point by this critical junction in development. If there was no testosterone (as in female fetuses), the breast tissue will continue to develop and mature. Since males have testosterone, the development of the nipples (and breast tissue) stop at this critical junction. Thus, men have immature breast tissue and the beginnings of fully functional mature nipples.

Answer 4

When we are a fetus we all start out as females. As the fetus evolves and the sex is established even if you become a male,the nipples remain!! Besides,without nipples,what else would a guy pierce-LOL!!!

Answer 5

Nipples form in the womb on the fetus before sex is determined. All mammals have nipples-male and female.

Answer 6

its like your appendix in that its no longer needed but you still have then if you want to know more this is from my link:
To tell you the truth, nobody really knows. The best explanation I've been able to find (and frankly it doesn't explain very much) is that nipples aren't a sex-linked characteristic. In other words, nipples are just one of those sexually neutral pieces of equipment, like arms or brains, that humans get regardless of sex.

As you may know, every human being gets a unique set of 23 pairs of chromosomes at conception. These fall into two categories. One pair of chromosomes determines sex--the XX combination means you become female, the XY combination means you become male.

The other 22 pairs, the non-sex chromosomes (they're called autosomes), supply what we might call the standard equipment that all humans get. These 22 pairs constitute an all-purpose genetic blueprint that in effect is programmed for either maleness or femaleness by the sex chromosomes. The programming is done by the hormones secreted by the sex glands.

For example, the autosomes give you a voice box, while the sex hormones determine whether it's going to be a deep male voice or a high female voice. Similarly, the autosomes give you nipples, and the sex hormones determine whether said nipples are going to be functioning (in females) or not (in males).

One interesting consequence of the developmental set-up just described is that during the very early stages of fetal life, before the sex hormones have had a chance to do their stuff, all humans are basically bisexual. Among other things, you have two sets of primitive plumbing--one male, one female. Only one set develops into a mature urogenital system, but you retain traces of the other for the rest of your life.

It's tempting, therefore, to say that male nipples are yet another vestige of your carefree bisexual youth. Trouble is, male nipples are hardly vestigial. They're full-sized and fully equipped with blood vessels, nerves, and all the usual appurtenances of functioning organs. Why this should be so nobody knows--in some other mammals, such as rats and mice, male nipple development is completely suppressed by the male sex hormones. (Incidentally, don't start thinking that at one time our human male ancestors must have suckled their young. So far as anybody knows, male lactation has never developed in any mammalian species.)

Human nipples appear in the third or fourth week of development, well before the sex characteristics. (The sex hormones start to assert themselves at seven weeks.) As many as seven pairs of nipples are arranged along either side of a "milk line," a ridge of skin that runs from the upper chest to the navel.

Normally only one pair amounts to anything, but on about one baby in a hundred you can detect some vestige of the other ones, usually on the order of a freckle. There are cases of women who ended up with an extra breast, which made them freak show candidates not so many years ago. Luckily today the women can avail themselves of corrective surgery while the rest of us can watch Jenny Jones.

Anyway, both male and female babies are born with the main milk ducts intact--the gland that produces milk is there in the male, but it remains undeveloped unless stimulated by the female hormone, estrogen. Occasionally, a male baby is born with enough of his mother's estrogen in his body to produce a bizarre phenomenon known as "witches' milk," with the male glands, suitably stimulated, pumping away at the moment of birth.

In the adult male, the dormant glands can still be revived by a sufficient dose of estrogen. Actual lactation is rare--only a couple cases have been recorded. But at least one writer (Daly, 1978) has suggested that the "physiological impediments to the evolution of male lactation do not seem individually surmountable." Meaning we may yet see the dawn of the truly liberated household.

Answer 7

Because we all start off female and then later on develop sexual characteristics of being a male. Nipples are leftover from that initial period.

Answer 8

because men and women are formed in the likeness of each other but hormones and the Y factor while in the womb are the distincting factors that separates men from women. a man can be xxy and so can a woman. a woman can facial hair or a penis
just like a man because of her production of testosterone.

Answer 9

to balance out the universe you without gravity we would fly off the planet and the waves in the ocean would be enormus but what keeps gravity here?

mens nipples!

Answer 10

becuase females do also an in some sort of way were related to monkeys and they have nipples to :) sounds corny but true

Answer 11

They form early before gender is assigned, and besides all fetuses start out female on a common development path.