why do men have nipples?
604629
Hmmmm, I read about that, trying to remember right.  When conception first takes place, the gender is not yet set.  Every baby intially can be male or female, the stem cells then become arms, heart, eyes, everything, including male genitals and prostate OR female genitals, womb and ovaries, and including the ability to grow breasts if the baby becomes a female.  Can't remember when it is that the gender becomes effective, but it's early on.
1156952
are you a male ? why would you need to pump your own nipples?
889565
Reason why male have nipples:\n1. To distinguish that they are mammals.\n2.A human baby inherits one copy of every gene from his or her father and one copy of every gene from his or her mother.\n3. It is the effect of the genes.\n\nReason for spleen:\nSpleen is a purplish-red organ shaped like a loose fist and located in the upper-left part of your abdominal cavity. It had been called "the most ignored and misunderstood of all organs." In ancient times, people believed it was the seat of the emotions, but actually it is an integral part of your immune system.\nJob description includes: \n1.filtering out foreign organisms that infect your blood \n2.removing your old or damaged platelets and red blood cells \n3.storing extra blood and releasing it as needed \n4.forming some types of white blood cells \nIf the spleen can be injured or diseased it can be removed through spleenectomy, you can live without it however,your resistance to infection will be lowered, at least initially. \n\nAppendix\nThe appendix is thought to have descended from an organ in our distant herbivorous ancestors called the cecum (or caecum). The cecum is maintained in modern herbivores, where it houses the bacteria that digest cellulose, a chemically tough carbohydrate that these animals could not otherwise utilize. The human appendix contains no significant number of these bacteria, and cellulose is indigestible to us. It seems likely that the appendix lost this function before our ancestors became recognizably human.\n\nSee my dear, this organs my not be vital as others but to maintain the human body in the state of balance equilibrium.
168127
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. \n\nAs 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. \n\nThe 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.\n\n\nWebMD\nMales and females, though very different, have a great deal in common. In the earliest part of our embryonic development, we all start out much the same. Though the sex of an embryo is determined when sperm meets egg, the genital anatomy of males and females cannot be visually distinguished with the use of ultrasound until the 15th week of pregnancy. \n\n\nFrom the beginning, we all have the tissues that later develop into functioning parts, depending on whether we are genetically coded to be male or female. (The genetic coding that leads to people who have both male and female anatomical traits is much more complex than we'll get into here.) \n\n\nMales have nipples because they develop with the capacity to be female should their chromosomes dictate. Females call upon this capacity when they hit puberty and their breasts develop. Later, if they become pregnant, they call upon it again as milk is created in their breasts. Generally, males do not have a reason for the nipple to function, although, from time to time, adolescent and adult males develop a condition called gynecomastia, in which hormonal levels fool the breasts into beginning to develop. \n\n\nBut for the most part, nipples are on men's chests not for ornamentation, but because we all initially originate from the same kinds of tissues. Males just don't need their breast tissue to be a functioning part of their anatomy
223449
Because they haven't quite finished evolving yet! Back when we were apes, every once in awhile Mama ape would go out with all of her girlfriends to the local cave tavern. Papa ape had to stay behind and feed Junior ape. Since there was no Mama ape around, and no milk man delivered any freshly squeezed milk from an anklysoaraus, then Papa ape had to resort to using his own nipples to provide Junior ape with the nourishment he needed to be a big strong hairy caveman.\n\nThe real answer is, because God created man with two nipples. End of story.
406989
In my undergrad biology days, this was actually discussed in a developmental biology class.\n\nMen have nipples because, at one time in the womb, they were female.  As the embryo develops, it takes the influence of genes located on the Y chromosome to allow the fetus to develop primary male sexual characteristics.  Up until that point, only the X chromosome is active, and nipple formation has already taken place.\n\nThe nipples are not a purely female trait; it's the mammary tissue in the breasts that are the real indicator.
1051631
It's the nipple.  Which begs the question, if nipples are obscene, why can men go shirtless?  \n\nA related story:  Many years ago a friend was busted for going topless on a Santa Cruz beach.  The above statement was her argument; and the judge ruled in her favor, so for a while it was legal to go topless in Santa Cruz.
2010
for foreplay ........ it can be very sensual for a man to have his nipples played with just as with a female ......... talk to your partner ..... ask him/her these questions and learn their likes and dislikes
867768
Answer this.\nWould you want to be showing your breast?\nAnd men dont have breasts. They have chests.
25734
Every egg starts developing in the womb as a female. The male genes kick in only later during the gestation. Consequently, an egg developing into a foetus develops nipples. After a certain stage, when the male genes kick in, the development of the breast is stopped. Thus men have nipple but don't have breast.
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?
1173882
ASK THE EXPERTS: BIOLOGY   \n \n \n \n \n \nWhy do men have nipples?  \n \n \nAndrew M. Simons, a professor of biology at Carleton University in Ottawa, Ontario, explains. \nLike all "why" queries, the question of why men have nipples can be addressed on many levels. My four-year-old daughter, always suspicious of a trick when asked such obvious questions, answered: "because they grow them." In search of the trick answer, she quickly added that "chests would also look pretty funny with just hair." \n \n \nADVERTISEMENT (article continues below) \n \n \n \nEvolutionary biologists, whose job it is to explain variety in nature, are often expected to provide adaptive explanations for such "why" questions. Some traits may prove—through appropriate tests—to be best explained as adaptations; others have perfectly good evolutionary, but nonadaptive, explanations. This is because evolution is a process constrained by many factors including history, chance, and the mechanisms of heredity, which also explains why particular attributes of organisms are not as they would be had they been "designed" from scratch. Nipples in male mammals illustrate a constrained evolutionary result. \nA human baby inherits one copy of every gene from his or her father and one copy of every gene from his or her mother. Inherited traits of a boy should thus be a combination of traits from both his parents. Thus, from a genetic perspective, the question should be turned around: How can males and females ever diverge if genes from both parents are inherited? We know that consistent differences between males and females (so-called sexual dimorphisms) are common--examples include bird plumage coloration and size dimorphism in insects. The only way such differences can evolve is if the same trait (color, for example) in males and females has become "uncoupled" at the genetic level. This happens if a trait is influenced by different genes in males and females, if it is under control of genes located on sex chromosomes, or if gene expression has evolved to be dependent on context (whether genes find themselves within a male or a female genome). The idea of the shared genetic basis of two traits (in this case in males and females) is known as a genetic correlation, and it is a quantity routinely measured by evolutionary geneticists. The evolutionary default is for males and females to share characters through genetic correlations. \n\n \nThe uncoupling of male and female traits occurs if there is selection for it: if the trait is important to the reproductive success of both males and females but the best or "optimal" trait is different for a male and a female. We would not expect such an uncoupling if the attribute is important in both sexes and the "optimal" value is similar in both sexes, nor would we expect uncoupling to evolve if the attribute is important to one sex but unimportant in the other. The latter is the case for nipples. Their advantage in females, in terms of reproductive success, is clear. But because the genetic "default" is for males and females to share characters, the presence of nipples in males is probably best explained as a genetic correlation that persists through lack of selection against them, rather than selection for them. Interestingly, though, it could be argued that the occurrence of problems associated with the male nipple, such as carcinoma, constitutes contemporary selection against them. In a sense, male nipples are analogous to vestigial structures such as the remnants of useless pelvic bones in whales: if they did much harm, they would have disappeared. \nIn a now-famous paper, Stephen Jay Gould and Richard C. Lewontin emphasize that we should not immediately assume that every trait has an adaptive explanation. Just as the spandrels of St. Mark's domed cathedral in Venice are simply an architectural consequence of the meeting of a v
162047
My ex had 3 nipples. When he was a kid someone shot him with a BeeBee gun. Hit him in the chest and caused a scar that looked just like a nipple.
22705
We are classified as mammals.  Mammals feed their young by the use of breast milk.  All male and female animals have nipples (what was God thinking?), but only the females have the hormones and additional physical items necessary to activate the lactation process.\n\nGender differneces stem from the X/Y genetic differences.  The rest of the body (including nipples) is controlled by genes elsewhere.\n\nStranger questions would be why do some women have Adam's apples or beards.  Nobody knows.
546211
When we are concieved the chromosones dont distinguish between male and female until after the nipples have started to develop.\n\nWith women the cells continue to specialise and produce breast tissue with men they don't.
754531
Your breasts are made of fat, skin, muscle and milk ducts, and other assorted things (like tubes to connect your milk ducts to your nipple, blood vessles, lymph nodes, etc)\n\nIn fact a male breast is made up of the same thing.\n\nMale and female babies can be born lactating because they are exposed to their moms hormones.\n\nSo you do not have breastmilk in your breasts but you are capable of making it if your hormones tell you to.
60697
The Straight Dope says, "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." \n\nIt's also notable that the fetus starts to develop nipples long before any other sex-linked characteristics.