Evolutionists: Did Men's nipples ever function like a woman's?

Question

Just wondering b/c in my medical classes we talk about men's mammary glands so I was wondering if they ever served a purpose since the don't have one now...

My class only said that mammary glands are present in both sexes, but only function in females. Why would we talk about them functioning in the past when a doctor wouldn't be treating anyone from that time?

EDIT: Okay people, I understand that every fetus in the womb is pretty much a female until the release of testosterone causes the formation of male features (I am in medical school, so I have learned some things along the way). That's not my question though. I just want to know if they functioned in the past and if so, why....

EDIT: Thanks JP...I think you are about the only one who's helping me out here.

Answer 1

Probably not. They're simply an analgous feature between the genders. Since they are relatively benign, it is likely they will remain since there is no selective pressure against them.

If there was to be a selective pressure put against them, you would anticipate that the male gender would lose them via either inhibition on the Y chromosome or migration of the necessary genes to the X chromosome and recessivity of the gene so only females would express them.

Already the fact that extremely few males are capable of lactation shows that certain features of the mammary system have been selected against (milk production requires a large amount of energy that in the male is wasted) and have thus become uncommon.

Answer 2

All embryos begin as female and the Y chromosome introduced at the proper developmental stage is what turns them into male. Several things are universal then, such as nipples. Men likely never had breasts that could produce milk except for the occasional mutation (the development process gets messed up occasionally and the original plan for milk-producing breasts can be unchanged by the Y chromosome).

Another example is the clitoris. All humans start with it, but for men it grows into the penis (and interestingly some rare women develop clitorises that are larger and more penis like - just as rare men have milk glands).

But these screw-ups are because evolution - while a powerfully elegant force - is not a perfect and genetics don't always replicate properly... Organic processes are really very sloppy and definitely weren't "designed."

Answer 3

Not that we know of.
Men have nipples because every zygote starts out female, and it takes specific hormonal kicks at specific times during gestation to make a male. Evolution hasn't apparently cared to devote energy to deleting nipples, but energy doesn't go into creating fully functional mammary systems in males.

HOWEVER...there are things that can and do kick off full mammary function in males. Side effects of several drugs (and a few natural substances) increase male breast size and can start milk production in males.

Answer 4

Every foetus begins as a female hence they all develop mammary glands however as men lack female hormones they don't develop into breasts on reaching adulthood.

Answer 5

Sorry but I'm an organist, not a medical professional. But remember in "Meet The Parents" when Robert DeNiro says to Ben Stiller... "I have nipples Greg, can you milk me?"

Best line in the whole movie!

Answer 6

They are vestigal organs, so probably. And if you're taking medical classes, you should already know the answer to that. If you don't, then ask the teacher. They can give you, and the rest of the class, much more thorough and informed answers than you'll find here.

Answer 7

Yes, they do.

Men are capable of lactating, and the reasons they don't are more social than biological.

In fact the Bible describes men suckling babies during the exodus, so it's not a purely "evolutionist" observation.

Answer 8

Yes - and they continue to today. Youre wrong about them not serving a purpose...

There are recorded cases in which men begin to lactate when their wives pass away and they still have very young children that need to be breast fed. There are recorded cases of this. Look them up.

Answer 9

No, they are remnants of every male mammal being a female for a short time while in the womb.

Answer 10

In the womb, we are all basically girls. Then, at a certain point, genetics takes over, and guys and girls go down a separate path of development to further stages.