So, why DO men have nipples?

[Dover]

So, why DO men have nipples?
New book seeks to answer unlikely medical questions

Wednesday, August 3, 2005; Posted: 12:05 p.m. EDT (16:05 GMT)



NEW YORK (Reuters) -- Have you ever wondered why your teeth chatter when you're cold, or if you could really catch a disease from sitting on a toilet seat?

New York physician Billy Goldberg, pestered by unusual questions at cocktail parties and other social gatherings over the years, puts the public's mind at ease in his book "Why Do Men Have Nipples?" (Three Rivers). The book hit stores on Tuesday.

"It's really remarkable how often you get accosted," said Goldberg, 39. "There are the medical questions from family and friends, and then there are the drunk and outrageous questions where somebody wants to drop their pants and show you a rash or something."

The book, subtitled "Hundreds of Questions You'd Only Ask a Doctor After Your Third Martini," is co-authored by humorist Mark Leyner ("Et Tu, Babe" and "My Cousin, My Gastroenterologist").

"People tend to know so little about their bodies as compared to their cars or their laptops," said Leyner, 49, of Hoboken, New Jersey. "When I worked in a pharmacy in Washington, D.C., people would ask me medical questions all the time. I was just a 22-year-old cashier at Rite Aid."

Desks vs. toilet seats
Goldberg had compiled a list of nagging questions for several years before embarking on the book after meeting Leyner. The two met while working on a short-lived ABC-TV medical drama, "Wonderland," in which Leyner served as a writer, while Goldberg was its medical advisor...cont'd

http://www.cnn.com/2005/SHOWBIZ/books/08/03/leisure.nipples.reut/index.html


Answer: While only females have mammary glands, we all start out in a similar way in the embryo, the authors explain. The embryo follows a female template until about six weeks, when the male sex chromosome kicks in.

Men, however, have already developed nipples by that time.

[meegbear]

1. Why do men have nipples?

Intelligent Design!

[Goldmund]

2. Took them words right out of my mouth!!!!

:rofl:

[tsuki]

3. Don't be askin' them kinda questions! It's Intelligent Design, I tell

you, Intelligent Design, and that's all ya need ta know.

[Ian David]

5. So we'll exercise our neck muscles trying to reach them when we're lonely

Or is that just me?

[givemebackmycountry]

4. Where else...

Do you think I'd let her put the clothespins?

God, what a stupid question.

:P

[WoodrowFan]

39. BOL!!!

:yourock:

[Ian David]

6. Here's what looks like a good, short answer...

<snip>

It seems that human embryos develop mammary tissue before they bother to check on whether they're going to be male or female and start modifying the basic plan with surges of this or that hormone. After only a few weeks, milk ridges form -- two stripes of tissue that start in the armpits, curve out over the chest, go straight down the stomach and then veer in toward the groin, ending somewhere high on each thigh. Later the milk ridges regress to some extent, usually leaving us with just two nipples.

More:
http://www.salon.com/health/feature/1999/06/08/nipples/

[Boomer]

52. Exactly right

Only no one seems to have bothered to read your message because they keep on discussing this issue with some rather outlandish theories.

[thereismore]

7. For nursing.

There was another thread about this.

I don't believe in Darwin's evolution of species. Some of you guys are laughing about ID, I am not. Anyway, if male nipples somehow agree or prove evolution of species, I would like to know your reasoning. Are you saying that males evolved from females but kept "vestigial" nipples? If so, how did the females reproduce? How do male nipples follow from evolutionary thinking exactly? I'm serious, tell me!

[Hav]

8. .

Actually the first post here and post number 6 attempted to answer that question. I suppose this specific is not really about evolution from females...

[RickWn]

9. Hope by now you've read the above answers

A lot of human evolution is contained in a developing embryo. Are you aware that there is a point when the developing fetus has gills and another where it has a tail?

[thereismore]

13. no gills and no tail. Sorry, they might look that way but aren't.

The "gills" are skin folds from which glands develop. The tail? We don't have tails (neither do apes have tails - monkeys do) are not tails. The last vertebae are used to anchor muscles for sitting and walking (gluteus). They have a totally different function from tails.

Both "gills" and "tails" are part of the long-discredited theory of "Ontogeny reflects Phylogeny" and Haeckel's fraudulent embryos presentation. Google it, you'll see.

[phantom power]

11. One argument might go like this:

Since men don't need them, an Intelligent Designer would not put them there. Since they are, in fact, there, it suggests that we were not designed. Vestigial structures are a characteristic of evolved systems.

[thereismore]

14. I don't agree. The error is in "we don't need them".

They can and have been used for nursing. Men are capable of nursing children, I assume it was needed when a loss of a mother would be the deatch of an infant otherwise.

[phantom power]

17. But they are poorly optimized. And we don't need them :-)

I was interested to learn that we men can make milk. It's hard for me to imagine tiny man-boobs making enough milk to feed a child. I guess it's better than nothing in a pinch.

[thereismore]

26. Many women worry that they will not have enough milk because

their breasts are "too small". No problem. The volume of milk does not depend on the volume of the breast, but on how fast they can make it. Believe it, they can make it as fast as the baby sucks. Size is not a problem.

[greyl]

23. No error in the statement "we don't need them".

If the survival of humanity depended on the ability of males to nurse their young for the past 3 million years, human males that nurse their young would either be a)thoroughly represented in the species, or b)we would already be extinct due to the loss of representation of breastfeeding males in our species.

Lactating males are definitely an anomaly.

[Igel]

12. It's mostly a commentary on evolution.

We have this quirky idea that everything that's present in a species is the result of positive changes resulting from evolution. But that's not what you'd predict. Sometimes getting rid of things isn't an easy task, and sometimes things that are selected for require waste elsewhere in the species--but, overall, constitute an advantage. (Menstruation, for example, is incredibly wasteful of energy and nutrients, but apparently does make for greater procreation rates.)

Some features are there because it's just how things went. Having milk patches (a la platypuses) is a great survival trait: but the way it was stumbled across made it a very early feature in gestation. When the tissue was concentrated in mammary glands, similarly, the tissue was produced early on in the womb. Apparently equipping males with mammary tissue that could be activated didn't confer an advantage, so it's mostly vestigial, but getting rid of the tissue in males would require that the tissue form late. And there may be good reasons for that not being feasible--it may be that one chemical signal saying "make mammary tissue" also says something like "make heart tissue" or "have arms grow here", so having the mammary tissue in males is a side effect of something really beneficial.

Or it may just be that the mutation never happened, and it could happen next week. Sometimes the mutations required for disposing of something just aren't worth it: so we still have an appendix. To get rid of it would involve a chance mutation, but most mutations are bad. If a mutation happened so that a person was born without an appendix--or nipples--that would confer at best a minimal survival advantage on the person, and there's no reason to think his/her offspring would become a greater percentage of the population than anybody else's.

Evolution isn't just driven by survival: it's driven by reproduction. If your kids, all brilliant and moral, are outbred by your neighbors' kids, all moronic and immoral, *they* win the evolution game.

[thereismore]

15. There's the appendix again. Did you know that the appendix is actually

an organ of the immune system? Because of its position at the beginning of the large intestine, it is probably useful for protection against bacterial spreading from the large intestine upwards. I know we can live without one, that doesn't mean it's an ideal situation.

[dwckabal]

18. Please supply some links

for your "arguements," preferably from reputible medical journals or the equivalent.

The clitoris is essentially a miniture penis; does that mean that a woman can fertilize her own eggs?

In regards to the link on male nursing, there were exactly two examples given, and some ridiculous bible passages. I'd say it takes more than two men in the history of humankind nursing to make the leap to "all men can produce breast milk."

[zalinda]

19. Okay, how about some more info

http://www.unassistedchildbirth.com/miscarticles/milkmen.html she's got a lot of links and info.

zalinda

[dwckabal]

21. Still doesn't support your thesis

that men have nipples so that they can nurse.

That men can nurse is not being disputed. You are simply begging the question. Instead, it's more likely the reverse is true: men can nurse because they have nipples. No revelation there.

[zalinda]

22. No one said that, please reread the thread

Nipples are on men because of the way humans develop in the womb, no one has said any different. We've just pointed out that they actually can be useful, rather than just decorative.

zalinda

[thereismore]

29. Here are a few in reputable journals

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3721289&dopt=Abstract

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3874811&dopt=Abstract

And there are more. I guess the way to approach this issue is to keep an open mind. It is not a good idea to just accept any dogma, like "the appendix is a vestigial organ, a proof of evolution". Just keep an open mind. There are a lot of things we do not yet know.

[greyl]

31. Are you're saying that male lactation may exist

because it will be useful in the future?

[thereismore]

33. All I know it's been useful in the past. n/t

[greyl]

35. When?

[thereismore]

41. documented cases here and there in this thread. I don't mean 1 mil

years ago necessarily, because I don't know for sure.

[beam me up scottie]

20. Sorry, but MOST of us are laughing at ID.

Not laughing like haha, but laughing like the very idea is so pathetic there are no words to accurately describe our disgust.

What's really funny is that you don't "believe" in evolution but yet you seem to think that men can lactate just as easily as women.

Anecdotal information, religious twaddle and a few documented cases are not proof that men are fully equipped and ready to become wet nurses.

Ian had the best link (from Salon) in post #6 above, so I'm just going to post more from that article:

In "The Descent of Man," Darwin suggests the possibility that "long after the progenitors of the whole mammalian class had ceased to be androgynous, both sexes yielded milk, and thus nourished their young; and in the case of marsupials, that both sexes carried their young in marsupial sacks."

Darwin defended mammae masculinae: "The mammary glands and nipples, as they exist in male mammals, can indeed hardly be called rudimentary; they are merely not full developed, and not functionally active." He suggested that ancestral males gave up the practice of nursing, after a prolonged period, perhaps because litters were smaller. When "the males ceased to give this aid, disuse to the organs during maturity would lead to their becoming inactive; and ... this state of inactivity would probably be transmitted to the males at the corresponding age of maturity. But at an earlier age these organs would be left unaffected, so that they would be almost equally well developed in the young of both sexes."
****************
Dr. Miriam Stoppard, author of "The Breast Book," agrees with Darwin that male nipples are more than rudimentary, cheerfully suggesting that "men could develop fully functional breasts given the right hormonal conditions."

That's right. If men would just submit themselves to an intense barrage of hormone therapy, affecting every organ system of the body in unknown ways, maybe they would be able to suckle their young and throw off the charge of reptilianism once and for all. But where is the research? Where is the funding? Where is the will?

Whither the male nipple? Is it ever likely to stomp off in an evolutionary snit over not getting any respect ("Enough about boar hogs!") and leave male humans as smooth-chested as stallions or bulls? It seems unlikely. They've managed to hang in there all these millennia, and many guys speak well of their nipples and would clearly vote to retain them. Ask any boar hog and he'll tell you the same.

So, sorry guys, unless you willing to undergo a long, really enjoyable series of hormone treatments or attach a breast pump to your nipples daily starting 6 months before your kid is born, (neither would actually guarantee you'd produce breast milk, BTW) you'll just have to sit this one out or be satisfied being a human pacifier.

I'm sure you're crushed.

[greyl]

24. As Jared Diamond said in that other link

http://www.unassistedchildbirth.com/miscarticles/milkmen.html

" the potential of biology - and medical technology - is vast....Brace yourselves, guys. Science is demolishing your last excuses. We’ve known for some time that many male mammals, including some men, can undergo breast development and lactate under special conditions. We’ve also known that many otherwise perfectly normal male domesticated goats, with normal testes and the proven ability to inseminate females, surprise their owners (and probably themselves) by spontaneously growing udders and secreting milk....Lactation, then, lies within a male mammal’s physiological reach.

Soon, some combination of manual nipple stimulation and hormone injections may develop the confident expectant father’s latent potential to make milk. While I missed the boat myself, it wouldn’t surprise me if some of my younger male colleagues, and surely men of my sons’ generation, exploit their opportunity to nurse their children. The remaining obstacle will then no longer be physiological but psychological: Will all you guys be able to get over your hang-up that breast-feeding is a woman’s job?

[beam me up scottie]

25. What an incredibly stupid thing to say.

"Will all you guys be able to get over your hang-up that breast-feeding is a woman’s job?"

I suppose he would be willing to have massive amounts of hormones injected into his body just so that he can nurse?

I say let's try it out on him first.

He could write an article detailing all of the fun things the hormones would do to his body.

And include pictures.

What an ass.

[greyl]

27. but I cited Diamond because he supported

the salon.com article. ;)
He's really not an ass as far as I can tell. I think when he said "Will all you guys be able to get over your hang-up that breast-feeding is a woman’s job?" with a casual attitude - it wasn't a call for men to breastfeed exactly. He was only speaking toward the potential of science.

[beam me up scottie]

30. So he's not the dude who "used the power of his mind"

and "willed himself to lactate"? :rofl:

I take it back then, he's not an ass and he's not making shit up like the author:

After he discovered that his body had indeed been responsive to his thoughts, he suggested to himself that the lactation would stop, and within a week his breast returned to normal. The experiment had been a success.

:banghead:

[thereismore]

32. I would not refer to male breastfeeding as a potential of science.

I would call it a fact of nature.

[greyl]

34. Sextuplets are a fact of nature

but that doesn't mean sextuplets are necessary or useful to human survival.

[thereismore]

42. I don't get it. n/t

[Kraklen]

45. Male lactation is a freak of nature.

It's like conjoined twins, only more so. It's not there by design.

[Kraklen]

28. For redundancy.

From the genome's perspective it's better to just give everybody nipples (and undifferentiated genitalia), and then figure out what get's used for where later on.

[thereismore]

36. When you say "it's better", in what sense do you mean better?

You mean it's a program more easily implemented in a human genome by a designer mind?

[Kraklen]

37. No, evolution.

Early mammals that all had nipples were more successful.

If it had been designed by God I think he would have done a better job and just given them to females.

[thereismore]

43. When you say "better job" what do you mean by that? Better in terms

of a minimalistic design or artistic design or whimsical design, or do you mean the current evolved design is somehow not quite where it should be?

[Kraklen]

44. aesthetics.

nipples on men are as useless as nipples on a bat suit.

I'm willing to bet there's some tangible disadvantage as well.

"do you mean the current evolved design is somehow not quite where it should be?"

This implies the common misperception that evolution has some sort of goal or destination that's reaching for. It does not.

My point is that there's numerous faults in human design, vestigial remnants that serve no purpose and only lead to harm, defects left over from bottum-up evolution. They certainly wouldn't be there if it was a part of a top-down intelligent design.

[thereismore]

46. Okay, I certainly understand your reasoning,

let me just point out some hidden assumptions in it:

1) when you say "They certainly wouldn't be there if it was a part of a top-down intelligent design", what you really mean is YOUR intelligent design (i.e., if YOU were the designer). To me that is a very strong assumption about a hypothetical designer of nature.

2) you keep mentioning "vestigial remnants". How do you know they are vestigial and not something not quite yet evolved? What if the appendix is on its evolutionary way to becoming a major new organ? Anyway, everything so far, including the appendix and male nipples, wisdom teeth and other stuff, turned out to have a function. Sure, we can live without them, like we can live without an arm or a leg. But that fact does not make them vestigial. If you want to call the appendix vestigial, you need to show that it's on its way out from the human race. You cannot do that. Among other "vestigial" organs, you might be surprised, were once listed such important glands as the thymus or thyroid. Textbooks from the 50's still call thymus a vestigial gland. What it shows is how great human ignorance is, even among learned people. We just don't know al there is to know about our "vestigial" organs.

I will leave it at that. I respect your opinion and I know how you think and feel, because I was once an evolutionist too.

[Kraklen]

47. hmm.

1. The "intelligent desinger" is God, Jesus's daddy, as described by the King James Bible. Maybe some sucker will fall for that particular trojan horse, I'm not about to.

2. We know they're vestigial because they have no function. Evolution doesn't create things that are half functional only to become functional later. We know they're vestigial because we can track them back the evolutionary ladder to times that they did function or have some purpose. Appendices, for example, or the blind spot.

Arms and legs have a function. They're still there for a very good reason. If somebody loses and arm and a leg they're in deep shit, as opposed to an appendix. It's better not to have one than it is to have one.

As for textbooks from the 1950's, I have a textbook from the 50's that still has "virginium" listed as an element. You're using errors in poorly edited textbook as an argument against science. That's a real Creationist type argument. No logic and often repeated.

I doubt you were ever an "evolutionist."

[thereismore]

48. Sure I was.

I have nothing to lie. By saying "I doubt you were ever an "evolutionist."" you are accusing me of lying. Why would I do that?
I don't like that accusation.

I was once an atheist. Now I am a Christian, a creationist, and a liberal. I trust you don't see that as a contradiction of terms.

thereismore

[Kraklen]

49. You're saying once upon a time men nursed babies.

No, I'm not saying you're lying.

I'm saying "I used to be an 'evolutionist'" is like saying "well, I've been a life-long democrat..."

[thereismore]

50. I don't get it. The two are very different to me,

and I only said the former. I don't ever say the latter. This is getting weird. Let's drop it okay?

[beam me up scottie]

38. Uh, Kraklen's not what you would call

a fan of ID.

:rofl:

[zalinda]

10. Some more info

http://www.unhinderedliving.com/nursingfather.html maybe more than you want to know.

zalinda

[thereismore]

16. Great link. Thanks n/t

[Xithras]

40. Because evolution chooses the efficient design, not the cleanest one.

Evolution isn't about improving species, but about keeping it existing and meeting its current needs. It's about biological systems starting simply and adding complexity to help species survive in their current environment. In the case of nipples, mammals need them to nurse our young, so evolution provided the simplest nipple design it could come up with while still being effective. Adding in switches to make them appear and vanish based on sex would have increased the complexity of the genetic triggers that create nipples. Since male nipples don't affect male survival rates, evolution never needed to develop that switch.

[Boomer]

51. Human sexual biology 101

All human embryos -- whether XX or XY -- start with undiffentiated gonadal tissue that will develop into a female if there are no hormonal instructions to do otherwise. If, however, the appropriate male hormone is generated (usually, but not always, due to the XY chromosome) during this early developmental phase, then the fetus changes direction to develop male genitalia.

The labia fuse and develop into testicles, the clitoris enlarges and develops into a penis. Secondary sexual characteristics of the female (such as breasts) do not develop during puberty.

If an XY fetus never receives the flood of androgen (due to androgen insensitivity or other hormone malfunctions) the fetus develops into a woman that is indistinguishable from a XX female, at least based on secondary sexual characteristics (hour-glass figure, full breasts, etc). The vagina, however, will be little more than a folded in skin pocket. So some individuals don't discover that they are XY until they fail to menstruate.

On the other hand, if an XX fetus receives a flood of androgen (often the result of medications the mother took during pregnancy), the fetus takes the developmental fork toward male genitalia, with an enlarged clitoris and at least a partially fused scrotal sac.

So we ALL have nipples because every fetus begins life developing as a female, and only the introduction of male hormone changes that developmental course.

Edited to add a link (one of many) on the basic facts:
http://encarta.msn.com/encyclopedia_761580700_2/Human_Sexuality.html