Male Nipples & Other Vestigials

Growing up, we had 3 books in our household: a bible, a German-English dictionary, and a big honkin’ Family Medical Guide – fully illustrated.


I used to spend hours with that medical book convincing myself I had everything from diphtheria to polio to lock-jaw to ectopic pregnancy.  At first,  I’d tell my parents about it, but they were always less than sympathetic, so usually I would just suffer in silence, leaving scraps of paper as bookmarks in the medical guide so people would know what I’d died from.

I’ve never lost that fascination with medical stuff. I should be a huge fan of Grey’s Anatomy, House, ER and such, but I’m not because I’ve also never lost the ability to imagine myself into a disease. And these shows feature some weird scary-assed diseases. So that’s probably also why it’s good that I never went to medical school. That and the fact that I rather dislike sick people.

So mostly I content myself with keeping up on medical news. Aside from the odd Ebola scare (that was a tough couple of weeks) or a Creutzfeldt Jakob outbreak (which was one thing I smugly knew I didn’t have), a lot of medical news just involves more drugs or vaccines being pumped into the market.

I like to see what’s going on with stem cell research and therapy, too because it’s always good to know there may be hope for a lot of these things to which one might be susceptible.

And, one of my favourite medical topics (and gee hasn’t it taken a long time to get to the point today) is vestigial structures in the human being.

These are things in or on our bodies that seem to have no purpose; such as nipples on men, the appendix, ear muscles[1], goosebumps[2], body hair, the coccyx (the last remnant of our tail days), facial muscles[3] or wisdom teeth[4]. Vestigials are very controversial because they were used by Darwin as proof of human evolution. Creationists have funded tons of research to prove that all these so-called vestigals do, indeed have a purpose.

At one time evolutionists had identified 180 vestigial structures in humans including the tonsils, the thymus gland, the pineal gland and the appendix – all of which are now known to have some very important functions.

It was only in the last year that the purpose of the appendix was discovered. It was once thought that it was just a shriveled up sac that used to help humans digest cellulose from things like plants and tree bark and as humans became more carnivorous we stopped needing that organ. After blithely yanking out kids’ appendices for decades, they now know that the appendix is a store-house of good gut bacteria that will release its stuff when necessary following a gut-bacteria killing illness like cholera or dysentery.

Male nipples aren’t really vestigials. They’ve never had a use as far as anyone knows. Nipples are formed in the 3rd or 4th week of human development with the fetus is still androgynous. Sex hormones come into play around week 7.

In some other mammals the male sex hormone then suppresses the whole male nipple thing, but not in humans.


Both male and female babies are born with perfectly good milk ducts in their breasts. Males retain this gland but it doesn’t develop unless stimulated by estrogen. Some male babies are born with enough of his mother’s estrogen is his system to actually pump out some milk (it’s bizarre enough to be nicknamed  witches’ milk).

In theory it’s possible to provide enough estrogen stimulation to an adult male to produce lactation – it’s been done a couple of times. Who knows where this could lead in the future?



[1] We still have ear muscles that used to be used to move the ears, like a cat’s, and do nothing now.

[2] Goosebumps were useful when we were covered in hair so they’d perk up our body hair when we got cold adding a layer of insulating air between hair follicles. Or, perking up the body hair when we got scared, making us look a little bigger and fiercer to scare away enemies.

[3] We still have the face muscles that used to hold up our heads, like they do in gorillas, but now we just use them for facial expression.

[4] Wisdom teeth are left over from when we had much bigger jaws and needed extra teeth to chew raw stuff. That seems like a pretty lame explanation to me, but that’s the best anyone could come up with so far.

29 responses to “Male Nipples & Other Vestigials

  1. Fortunately the gall bladder is un-necessary, if not downright vestigial, since mine was removed about 25 years ago. I’m wondering when our index fingers will become vestigial and stop showing up on new babies, seeing as how everyone texts with their thumbs.

  2. Interesting! I too read medical books. Of course, I will read a cereal box if I have nothing else to read. Unfortunately, I read fast enough that ocasionally it gets real interesting.

    Like reading “Cartoonist” for “Creationist” in your blog today. I had all kinds of pictures going on in my head with that one.

    And, I have re-read this comment, this time to try to avoid all the typos I had in the last comment I posted on your blog. Sorry, about that.

  3. I thought wisdom teeth were because our teeth used to rot out from no dental care and they would come later to fill up empty space and allow us to eat.

  4. XUP, I’m just wondering if you’ve ever had sickle cell anemia or problems with your prostate gland. If you have, you sure recovered well.

    I’m also wondering whether the sorry looking people in the top illustration wax or shave, and whether they waxed or shaved themselves or each other.

    Add to useless things in our bodies the clavicle (collarbone) as noted in an earlier comment to an earlier post. And, of course, in a lot of people, the brain goes totally unused and unrecognized.

  5. Meanie – Pineal gland, eh? I hope there’s a blog post in there somewhere because I can’t imagine what the backstory to this comment could be.

    Alison – The gall bladder isn’t vestigial at all – you need it to help you digest fats. Do you have any problems if you eat a really fatty meal?

    Kimberly – Ouch. And how freaky?

    SaVanVleck – Yes, those damn cartoonists always objecting to the theory of evolution.

    Tiana – That’s actually sort of what happened to my tonsils. I had almost constant tonsilitis when I was a kid, but my doctor (very forward thinking) didn’t remove them. They ended up pretty much rotting away from infection and so one day the doctor decided what was left of them should probably come out. Never happened. Time passed. The doctor retired. Next time I had a check up the new doctor remarked on what an amazingly healthy set of tonsils I had. Ta –da! I grew new ones. I’m awesome, no?

    Bob – I’ve heard that about the clavicle. It sure seems to cause a lot of pain for something that does nothing, though. And yes, those specimens above sure do look pathetic. It’s from an actual ancient medical book.

    Grouchy – Thanks.

  6. I actually can move my right ear up and down. I can’t remember how I discovered this. Left ear – nothin’.

    And for the record? That picture of the dude breastfeeding may be the singular most disturbing thing I’ve ever seen on your blog. And THAT is saying something.

  7. You have excellent timing – I’ve just started to read “On the Origin of Species” for FYP. It’s a fascinating to read the work that revolutionized scientific thought, especially after having read all of the Christianized stuff, and the reactions to Galileo, &tc. I didn’t know they had figured out the use of the appendix. Now I’m glad I didn’t get mine removed, like I wanted to when I was 8 (I just wanted ice cream, God damn it!).

  8. Um, how do we tell Davis that the ice cream pig-out comes after a tonsillectomy, not an appendectomy?

  9. Jazz – Close, they’re old time Germans with a lot of medical issues, apparantly.

    Lesley – Oh come on now! There are far more disturbing things on this blog. Those saggy, totally despondent people at the top for instance with hypodermic needles sticking out of their arms — that’s pretty disturbing isn’t it?

    Davis – Ya, I troll all school curricula in advance and plan my blog posts accordingly. And, um — please see Bob’s comment below regarding the ice cream thing.

    Violetsky – I wonder if this is how men feel about seeing women breastfeeding? He seems to have garnered a lot of negative responses here.

    Loth – I wish I knew all this stuff off the top of my head, but I just read it and think “hey”… and next thing you know it’s on my blog.

    Bob – Break it to her gently, Bob. Maybe over a big bowl of ice cream. Bring the drawing of the sad folks above in case you need visual aids

    Jobthingy – ‘Nuff said.

  10. I am just watching House, getting his nipples tweaked to get him breathing again (exhausted from being in a ‘good mood’ for the last 20 minutes?). See, there is a purpose.

    Maybe. But it is just so unnatural, that daddy breastfeeding. Mummy, yes.

  11. The sad, saggy, needled-up people at the top ARE disturbing. I’ll give you that. But they are still running a distant second. Because, you know, um…EWE????? (Great post, though! Did I mention that??)

  12. Okay, I’m fascinated.

    Why did we stop using those ear muscles? What would make us stop moving our ears around to hear? Laziness?

    and I don’t understand (I’m certain it’s my own shortcoming) about the gorilla: face muscles holding up the head. What do you mean holding up the head? We still hold up our heads, don’t we? splain.

  13. LoLa: this is completely speculative, but I suspect that we stopped using ear muscles when our ears moved to the side of our heads, and we were able to use stereoscopic hearing to locate the direction from which sounds come.

    – RG>

  14. I’m with LoLa: VERY creepy pictures in the medical book.

    Also, I was once asked by one of my Grade 1 students why boys had nipples, since they would never use them to feed babies like girls would when they grew up. I can’t remember exactly what I answered, but it was something along the lines of “We are all made from the same design to begin with, then we change here and there.” That put him onto musing why some parts changed and others didn’t, and how your body even knew whether you were a boy or a girl … That drove me crazy. We went on to a Math lesson.

  15. My tonsils were removed when I was young-a horrible experience-I just hope I never need them for whatever. Interesting reading. I’m a nurse and was sure I had a few medical problems as I was going through school but sure glad I didn’t.

  16. Geewits – Ha ha, that’s funny – she actually does look like the Queen. I never noticed. Man, it’s amazing what a shiney gown can hide, isn’t it?

    Violetsky – House? Good Mood? Nipple tweaking? Hmmmm. And, yes that poor man just doesn’t look right with his swollen bosom full of manly milky goodness.

    Lesley – Well, I’ll have to think of something to disturb you even further.

    Jobthingy – No, really, it’s an illustration from an old German medical guide. Is it any wonder I was rivited to this stuff when I was a kid?

    LoLa – Well, we don’t need to watch out for predators or listen for prey anymore, so our ears don’t have to pick up tiny sounds in a multi-directional way. Also, what RealGrouchy said. And the gorilla (and presumably old timey humans) had really, really big heads which needed a lot of holding up. Our tiny heads now can be held up with whatever tiny muscles we have now. You can look it up. The internet is full of amazing stuff like this. (including creepy pictures)

    RealGrouchy – Yes. Also we don’t need the acute sense of hearing we once did presumably.

    Pinklea – Well, now you have a definitive answer. We all maintain the same parts throughout, it’s just with the influx of sex hormones to the fetus, some parts develop differently in males and some differently in females.

    Linda – Aren’t you brave! I seriously think with enough encouragement I could actually imagine myself into actually, really developing a disease. Ever time I’ve watched ER or one of those shows I lay in bed at night unable to sleep thinking about the possiblity of all that freaky stuff going on inside me or my kid.

  17. I loved reading the medical book that my parents recieved from Reader’s Digest. Of course, and not surprisingly, my favourite section was the one on sexuality. Although, somehow, I just knew that there had to be more than just the missionary position…

  18. Woodsy – Yes, that’s where I got all my preliminary sex information, too. It all sounded incredibly complicated and boring. It wasn’t until Grade 7 that we started getting more of the human side of what sex was all about — although a lot of it was misinformation at that point, too. I guess the majority of my sex education was on-the-job-training

  19. very cool post! i too am very interested in medical things, i can look at gross stuff and just be fascinated with it all. i’ve heard doctors and nurses or other medical folks say that they too would “come down with” all of the diseases and sicknesses they were studying at the time. in fact, i think that is a typical human behavior to mimic each other without even realizing it.

    i’m referred to as “the hypochondriac” in our family, and it was true on some levels, more than anything it’s an indication that something isn’t “sitting right with me” emotionally. at least if it’s ongoing stuff, not the common cold or allergy attack.