Vestigial traits in humans

March 19, 2016 • 1:00 pm

Here’s a new video from Vox that demonstrates several vestigial traits in humans. Most of these are in WEIT, but this is a great short video to show students.  I don’t have a palmaris longis on either arm, but I can wiggle my ears. Still, I didn’t know that you can detect futile attempts to move your ears by looking for activity in the ear muscles, which is really cool.

Two years ago I put up a post on the palmar grasp reflex, with videos as well as photos of my friends’ babies demonstrating the trait (it’s in both hands and feet). Go over and see the fun.

I was never able to persuade anybody to try suspending their babies from a stick, even with lots of pillows underneath. Think of the science!

h/t: jsp

22 thoughts on “Vestigial traits in humans”

  1. Who knew? I have the Palmaris longus, it’s much more developed on my RHS than LHS which is what one would expect I guess, as it is my dominant arm / hand.

  3. I can flare my nostrils.

    P.S. Can we have more pics of food? Much much many many more pics of Indian noms…. pleeeeeeeeze? Hmmmm hungry…

  4. That is pretty good! The example of a ‘tail’ shown in a baby is a soft and boneless extension and creationists will always point out that it is therefore not really an atavistic tail.

  5. I’m Jerry’s evil twin! I have palmaris longis on both arms, but can’t wiggle my ears.

    Seriously, though, what do creationists babble say about this? The standard non-explanation for things such as schistosomiasis and cancer is “the fall” (because their god is a sadistic bastard), but what about cute or meaningless vestigial traits? Or men’s nipples? I googled, read a little on creationism.com, and nearly lost my lunch.

    1. What I remember from my misguided years as a creationist is that they first assume that “vestigial” is synonymous with “useless,” and then say that since so many vestigial organs have been found to have functions–like the appendix in the immune system–we’ll eventually find functions for them all, and thus there won’t be any more organs left to call vestigial. Of course, I can see now that’s a flawed argument because 1) just because something’s vestigial doesn’t mean it can’t be used for anything, and 2) some parts of our bodies, like men’s nipples, really are useless and I highly doubt we’re going to find that they serve a purpose.

      1. Never mind; it’s satire. That’ll teach me to share something before reading it.

    1. Then it must be a miracle!
      Now…can you wiggle one ear without the other one moving?
      😉

  8. Is it not possible to learn to wiggle your ears? As a child I could not wiggle them but thought I could learn. I noticed my ears moved if I raised my eyebrows, so it was just a matter of learning to move those other muscles while keeping my eyebrows still.

    1. I think yes. When I was young I practiced raising one eyebrow to be like Mr. Spock, and after a time I got pretty good at it. But I still can’t raise the other eyebrow. ;|

      1. I taught myself to do either eyebrow like spock and the Elvis lip sneer with a finger until the muscles could do it alone.

        sort of like Lillian Gish in Broken Blossoms.

        I can only curl my tongue with one fold and I understand that’s a genetic trait.

  9. This was a great video, but they left out my favorite vestige: the inner eyelid. I’ve long wondered, if some rare people have been born with a tail, is there anyone alive today with a fully-functioning inner eyelid?

  11. > I was never able to persuade anybody to try suspending their babies from a stick, even with lots of pillows underneath.

    Something over 40 years ago, my lecturer in physiological psychology claimed that he had tested the grip reflex with his own newborn (really newborn, he said). He had no photographic evidence, though.

  12. Well I have the palmaris longis , more evident in the Right as opposed to the Left,I can’t for the life of me waggle my Ears ar raise a single Eyebrow, but one of my Sons can. to my chagrin.

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