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  4 0 Lidi was mostly right but what I feel is important to emphasize here is that natural selection doesn't work on one sex alone. If it did, you would inevitably see animals that looked morphologically very different from one another, as though they were ACTUALLY members of another species. This CAN happen, but only does when extreme sexual dimorphism becomes an advantage. You have to think of male and female members as being part of a larger gene pool, one from which both sexes draw. Natural selection will alter that gene pool over time, making additions and subtractions, paving over certain spots and enhancing others. In fact, many of the genes men and women share contribute to sexual differences in the presence of different hormone levels. It's much more difficult for natural selection to act on these genes in a way that affects both sexes positively. Female mammals have nipples because they serve such an obvious purpose...but there is no similarly negative influence on male mammals to NOT have them. On the flip side, if a man was born WITHOUT nipples, that might be just fine, but if his daughters, in turn, were also born without them, that unique genetic code might be weeded out, over time. Arsenic7 answered in News & Politics over 2 years ago | Report 1 comment by money… 0 0 Good answer! You correctly identify that natural selection acts on the gene pool, but you could be more clear about hormones. Hormones are proteins which must be translated ultimately from DNA - 'genes' - which natural selection is free to equally act upon regardless of level of protein expression. Furthermore, DNA that encodes maladaptive hormone levels (ie that which might change the sex away from the genotype and thus make it 'difficult' for natural selection to act on a gene pool) are likely to fade to extinction in mammals. Good point on correctly identifying that a man w/out nipples might have trouble conceiving a daughter! money commented over 2 years ago | Report Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  4 0 For my exclusive sexual pleasure. Miss Foxtrot answered in News & Politics over 2 years ago | Report 1 comment by Violet DaGrinder… 0 0 WIN Violet DaGrinder commented over 2 years ago | Report Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  4 0 Because the angels need something to grab onto when we die. And they sure aren't touching that other thing. Lilting Missive answered in News & Politics over 2 years ago | Report Comment on this answer Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  3 0 If men didn't have nipples, the bellybutton would be a far less convincing mouth for torsoface. RJF answered in News & Politics over 2 years ago | Report Comment on this answer Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  3 1 Because there is no reason for them to not have nipples. Embryos are all basically female until the hormones kick in and boy-babies develop male characteristics; nipples are part of the default set of body parts, and it's just hormones that turn female nipples into functioning organs while male nipples are usually only good for fun and decoration. Evolution-wise, there's no reason why natural selection would promote the continued existence of man-nips, but there's also no reason why there would be selection against male nipples. They're neither helpful nor harmful, so they continue to be part of the human genome without much change throughout the eons. If there was some reason male nipples were harmful to a guy's chances of fathering children they might have gradually been bred out of the population, but since they don't have much impact either way they've stuck around. Lidididi answered in News & Politics over 2 years ago | Report 9 comments by Lee, Lidididi, and Lee… 0 0 Of course, this isn't specific to humans: all mammals share this trait, and it's in fact one of the distinguishing traits of mammals. Also, I don't think it's correct to say early embryos are "basically female." There's no sense in defining the sex of something prior to the development of any sex traits. You could distinguish by chromosomes, but even that isn't entirely reliable. Lee commented over 2 years ago | Report 0 0 I say they're basically female because the Y chromosome triggers the hormones that cause male sex differentiation; in the absence of those hormones the embryo will develop into a female. Female is the default form, and extra hormones are needed to develop into a male. from http://www.narth.com/docs/berman2.html : "we all begin life as a proto-female, and that a few males end up with a low-masculinized brain. What is the evidence that life begins for all of us as proto-females? We all have nipples, that's the evidence. As Leyner and Goldberg put it, "During development, the embryo follows a female template until about six weeks, when the male sex chromosome kicks in for a male embryo." But before the end of the sixth week, a pair of sweat glands on the chest has already begun to differentiate as nipples. All infants are therefore born with nipples and some breast tissue. As they approach puberty, the female hormones that course through the bloodstream of girls reshape their body in womanly ways, including the development of their breasts. Males are left with vestigial nipples, a reminder that life begins for all of us as proto-females, and some of us are fated to become more masculinized than others." Lidididi commented over 2 years ago | Report 0 0 You're citing a NARTH writer? Really? Sorry I up-voted your answer. Lee commented over 2 years ago | Report 0 0 oh shit, i didn't look too closely at that author. i just searched for a summary of Leyner and Goldberg's explanation of the nipple thing. Lidididi commented over 2 years ago | Report 0 0 For the record, Leyner and Goldberg have nothing whatever to do with NARTH, but instead are the authors of a popular book called "Why Do Men Have Nipples: Hundreds of Questions You'd Only Ask Your Doctor After Your Third Martini". Fnarf commented over 2 years ago | Report 0 0 It's worth pointing out that, when testosterone fails to work (so to speak) for a male fetus, it ultimately becomes female, although without functioning reproductive organs. keshmeshi commented over 2 years ago | Report 0 0 In humans, calling an embryo a proto-female is a terrible simplification, especially considering that its genotype is either XX or XY immediately following fertilization. Charitable readers will acknowledge that science has not yet advanced to the point of knowing for sure if the female or male came first, although substantial evidence points to the female. Yet, one could presume that within that female is the full capacity to produce a male through sexual reproduction, so all of the physiological capabilities to be either male or female are present from day-1 whether you want to say that it looks more like one or the other. I think it would be prudent to keep it at 50-50 save for certain specifics. Does this reflect my bias as a male - possibly. money commented over 2 years ago | Report 0 0 What can it possibly mean to say "the female" came first? Every human that ever lived, and every prehuman they descended from, came from sexual reproduction -- male and female both. This has to be true at least as far back as the first human, and every mammalian stage of evolution before that, at the very least. Fnarf commented over 2 years ago | Report 0 0 I too don't really understand what it means to say one sex came "first" (with all due deference to the numerous easy jokes you just thought of). Sex distinction exists on a continuum. Single cell animals don't have this trait at all, and more complex creatures are often hermaphroditic, and produce male or female zygotes depending on the moonphase or wind. One thing's for sure: mammals in general have strong sex distinction, and rare incidences of hermaphroditism. The "first" of whichever sex arrived long before the first human, or even primate, did. Lee commented over 2 years ago | Report Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  2 0 To nibble on during foreplay. Ed B answered in News & Politics over 2 years ago | Report Comment on this answer Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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  0 0 We know why males have nipples. I think the real question here is why don't males breast feed, since all mammals have nipples? money answered in News & Politics over 2 years ago | Report Comment on this answer Enter your comment or ask a new question preview THIS IS A PREVIEW: Click "Post" to submit it or "Edit" to make changes. edit Please wait… This could take a minute if the tubes are clogged.

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