Why do human males have nipples?
486251
Because when they are a fetus in the womb both males and females grow in the same way upto a certain time when sexual charcteristics develop. \nMales stop growing in that area cause they do not need them for survival whereas females need them for breastfeeding so development continues.  \n\nI think apes have them to!
1122905
Before asking that question, you need to understand what evolution is.   Evolution describes genetic change over time in response to environmental selection pressures on a species.  This means that advantageous changes are not weeded out.  In fact, all traits which do not negatively impact survival or reproduction, will not be weeded out.  Nipples on a man fall into this category.  Further, if anything, nipples are PROOF of evolution - In general, all species evolved from a prototype ancestral condition; thus, there exists genotypic and phenotypic similarities between members of a species and between related species.  All mammals have nipples, male or female, because our earliest mammalian ancestor had nipples (in fact, what makes us all "mammals" is the ability to produce milk via "mammary" glands to nurse our young).  Thus, both genders of our species (and all mammalian species) have nipples.  Nipples are a conserved evolutionary trait and are not gender-specific.
658338
Males and females develop from a similar template in the womb. Before about 3 months the fetus is sexually undifferentiated, and distinctively male or female genitalia develop from a similarly structured organ, i.e. testes and ovaries both develop from an undifferentiated gonad. So males have nipples because of similarities between males and females before sexual differentiation occurs. \nHowever, it actually is possible for some men to produce milk in small quantities under some circumstances. Apparently men who play with their nipples alot may start to produce milk! Some men also produce milk when their wives are pregnant! Sort of like a sympathy response.
734061
Men don't develop breast tissue, but they do have nipples.  All humans at one point in time are a woman.  It all depends if the Y chromosome is present or not.  If it is, the body sends out testosterone changing the woman to a male.  The organs "down there" change to male organs, but the nipples just stay where they are.  So in a sence, men have nipples because women have them.
1164409
The same reason little kids can go topless.  There is nothing to see.  You see, a woman's breasts are a private, personal thing.  They are all different shapes and sizes, the nipples are MUCH larger than men's (in most cases), and they are used to feed children.\n\nPlus, think about how much you stare at men's pecs compared to how much they stare at your breasts.  Do you really want them to be able to see them any time?
1030685
None. Males and females are essentially the same during development until a hormonal event causes males to develop male genitalia. Because of this, we have some of the same physical characteristics and thus males have nipples.
1156952
are you a male ? why would you need to pump your own nipples?
62582
Many scientists believe that male nipples are an evolutionary vestige which is simply the result of males and females shareing virtually identical genetic structures.  Some evolutionists belief that evolution has not phased male nipples out because there is no evolutionary advantage to phasing them out.  Also, male nipples do serve a limited function in sexual arrousal.  Further still, male lactation does occur, though rarely, and is no doubt the result of the simularities in the genetic code with females.
11936
Somebody knows, ask an anatmoist. Nipples show up on a fetus before the fetus starts producing sex hormones (estrogen or testosterone). At this point in development the fetus is neither male nor female in appearance. Sex was determined at the moment the egg (X) was fertilized by a sperm (X or Y). This debunks the myth we all started female. As to why nipples develop so early, no one knows that answer.
60214
A human embryo begins developing as a female (or some say anatomically indistinguishable), complete with mammary glands and ducts.  A couple of months later the hormones kick in and well...boys will be boys.  Most people (scientists, researchers, et cetera) say the nipples are from that "indistinguishable period."\n\nAs far as all land mammals having nipples, I had to Goooogle that one.  The site I found said all land mammals have nipples except stallions.
86011
Males also have the hormone estrogen. Estrogen menlarges breast size. Women have more of it, so they have bigger breasts. They also have luteniezing hormone which produces milk for mammary glans after giving birth. Men do not have that. Women displaying male qualities like beards have an excess of testoserone and androgen
392368
Men's nipples don't have a purpose.  When a baby is developing in the uterus, they all start out as female, hence the nipples developing.  Basically in order for a male to develop from there is a genetic fluke which sends signals to start developing male organs.  The only sign that is left that all men started as females at the most basic level of life is the nipples.\n\nFascinating, huh?
20048
Men and women are mammals (from the Latin mamma breast) a species that have breasts and feeds its young with milk. The human embryo has tissue that will evolve into breasts. Both male and female babies are born with nipples and ducts intact. It is the presence of genes that direct hormones to differentiate the breast tissue. The Y chromosome stimulates hormones such as testosterone to form male features.\n\nInsufficient or defective testosterone, poor tissue responsiveness, or an unbalance of other hormones like Estrogen and Prolactin can cause female like breasts even in men (Gynecomastia). At birth, the small amount of the mother's estrogen in the baby can result in small breasts that usually resolve. There can be an inbalance of hormones during male puberty that can result in temporary breast growth, which for most resolves. There are many medical problems and drugs that can cause male breast growth.
128418
Every animal comes from a "generic" base model.. the "Y" chromosome chooses to make that base model male.  All body parts translate into some part or another between the two sexes.  So, men AND women therefore have nipples.
511919
Nobody has produced the right answer ... it is a perfectly valid question.  (He is not asking whether women *should* have orgasms ... he's asking if there is any biological or evolutionary function for it.)  I have an old lecture by evolutionist Stephen Jay Gould on CD and he addresses this specific topic.\n\nThe answer is the same for "why do men have nipples?"  In early stages of embryonic development, males and females are physically identical.  At a certain point the body differentiates.  The same nerve-concentrated organ that forms the penis in males also forms the clitoris in women.  And the same nervous system cycle that produces orgasms in males (and is important for reproduction) has a corresponding effect in females (and has no reproductive function).  The details of the orgasm are different between males and females, but both have them.\n\nFemale orgasms do not seem to assist in reproduction at all. It could be theorized that orgasmic females would tend to have more sex, and therefore reproduce more, but this doesn't seem to be a factor in most species in which there is no evidence of female orgasm.  It is just a happy accident in humans.
144593
Just in case you want a serious answer, men have nipples because during the early days of a person’s development (fetus) everyone is female. Males become males later due to hormones. The nipples are created before the hormones kick in.
449265
most men, gay or straight, were breast-fed.  i think there's just something biologically comforting about breasts, as the original source of food and affection.  as women, we have our own, but men must be drawn to them on a subconscious level, even if they're not sexually interested in the woman.