The vestigial grasp of infants

In WEIT there is a chapter on vestigial traits, defined as those traits that are evolutionary remnants of features useful in an ancestor, but now either useless or used in a different way.  The paradigmatic case is, of course, the appendix, the remnant of a caecal pouch used to digest leaves and vegetation in our ancestors. But behaviors can be vestigial, too.  One such behavior is the “grasping reflex” of human infants.  When you put your finger into the palm of an infant, it will immediately and securely grasp it.  The grasp is so tight that it’s sometimes hard to make the kid let go!  It is said — though I have never seen this demonstrated — that up to a couple months of age a baby can hang suspended from a horizontal stick for several minutes.

The grasping reflex is evident in the feet, too. If you put your finger along a baby’s toes from the sole side, it will grasp with those toes.  And when a baby is sitting down, its “prehensile” feet assume a curled-in posture, much like what we see in an infant or an adult chimp.

One of my friends has a four-month-old daughter, and I asked her to take a picture of the grasping reflex and the prehensile foot posture for this website.  Here are both in a single picture.  Although the kid is somnolent, she still holds on firmly.  The sitting posture of a young chimp is given for comparison.

grasping instinct

Chimp sitting 9

Why do infants show this grasping reflex, but then lose it after several months?  A very plausible suggestion is that the behavior is a remnant of the grasping reflex seen in other infant primates, which they use to hold on to the hair of their mothers as they’re being carried about.

I’m not going to encourage my readers to suspend their newborns from broomsticks in the cause of evolution (they could fall, after all), but if you’re sufficiently curious and foolhardy to do this, let me know the results.

Thanks to the anonymous mom who donated her child to science.

THIS JUST IN:  Photographic proof! (Thanks to commenter Wes for the link.)

brooks2.450

Video proof (hat-tip to feelx):

69 Comments

  1. John D Stackpole
    Posted July 16, 2009 at 1:18 pm | Permalink

    “Donated her child to Science”

    Gee, I hope mom got her child back..

    (Talks about your unfeeling atheists…)

    • Posted July 16, 2009 at 1:28 pm | Permalink

      Gee, I hope mom got her child back..

      (Talks about your unfeeling atheists…)

      The atheist scientist probly ate it.

      After all, they have no morals.

      Glen Davidson

      http://tinyurl.com/mxaa3p

      • Posted July 16, 2009 at 2:19 pm | Permalink

        But we do have excellent baby recipes, don’t we?

      • Sili
        Posted July 16, 2009 at 2:40 pm | Permalink

        But they’re so delicious!

        Don’t most people lose their ethics when they’re served foie gras, too?

      • Kyle
        Posted July 16, 2009 at 7:17 pm | Permalink

        But I don’t want to eat babies! I have 3 reasons!

  2. Hongkongjohn
    Posted July 16, 2009 at 1:20 pm | Permalink

    omgay, that chimp is so cute! :O

  3. Leslie
    Posted July 16, 2009 at 1:21 pm | Permalink

    There’s also a stepping motion infants do for a short while (long before the ability to walk). I wonder what that is a hold over from?

  4. Posted July 16, 2009 at 1:26 pm | Permalink

    Using this with IDiots and other creationists would probably end in a lot of blather about possible functionality, although evolution seems to be the most parsimoniuos explanation for it.

    I think that gooseflesh is one of the best examples of vestigial function in humans. Whatever functionality it could have now is decidedly minimal, hardly anything that a thinking person would expect a being who designed us to be nearly hairless would include.

    Like most good evidence for evolution, IDiots almost always ignore something like that, or the infant’s grasping reflex, and rarely with dithering nonsense that typically tries to deflect the question. After all, it’s not about understanding biology, it’s about proving god, so everything that scientists want to understand is expendable.

    Glen Davidson

    http://tinyurl.com/mxaa3p

    • John Copeland
      Posted July 17, 2009 at 8:05 am | Permalink

      I believe the phenomenon you refer to here is when your skin contracts due to you feeling cold. Therefore the meaning for this in the present becomes quite obvious. I suggest that the next time you try to mock others, you do a little research.

      • Happy
        Posted July 17, 2009 at 12:25 pm | Permalink

        You neglect to mention that goosebumps also happen when were scared. They work rather poorly to warm us up when were cold, and they’re utterly useless for when were scared. If only we still had fur…

      • Pseudodog
        Posted July 17, 2009 at 12:30 pm | Permalink

        It’s not your skin, it’s the hairs embedded in your skin. It’s not something passive…your body actively does it. To fluff up your fur so you stay warm. Which you don’t have.

        I suggest that the next time you try to mock others, you do a little research.

      • BdN
        Posted July 17, 2009 at 12:53 pm | Permalink

        And when piloerection happens in other mammals because they are scared or threatened, it makes them look bigger. I doubt that goosebumps per se make you look that big… As Happy said : if only we still had fur…

  5. Posted July 16, 2009 at 1:37 pm | Permalink

    The child is holding on to the last vestiges of her youth (drum roll).

  6. Posted July 16, 2009 at 2:20 pm | Permalink

    If the human babies use the grasping reflex to hold on to their mothers, then it isn’t really vestigial, yes?

    • CW
      Posted July 16, 2009 at 2:31 pm | Permalink

      Vestigial does not mean “useless”, just that it has lost its _original_ function (or much of it).

    • Michael Heath
      Posted July 16, 2009 at 7:43 pm | Permalink

      If it wasn’t vestigal, they wouldn’t lose the trait.

    • BdN
      Posted July 17, 2009 at 12:39 pm | Permalink

      And they don’t really have anything to hold on to… I don’t think mothers were walking while holding their infants by their fingers…

  7. Posted July 16, 2009 at 2:27 pm | Permalink

    Interestingly, that “grasping” motion of the foot in infants is, in adults, a symptom of MS. I forget what the technical term for it is, but if you run a somewhat sharp point (like a sharpened pencil) along sole of the foot, in adults the toes should spread out. In infants and those with MS, the toes curl inward.

    I have no idea why.

    • CW
      Posted July 16, 2009 at 2:37 pm | Permalink

      That’s actually backwards. The normal response is to curl the toes downwards, with MS and other neurological conditions there is, instead, an extensor response and the big toe curls upwards. (It’s called
      Babinski’s reflex.) Interestingly, in babies under about 2 years old the reflex is inverse and they exhibit the extensor response.

      • amphiox
        Posted July 17, 2009 at 4:50 pm | Permalink

        A noxious stimulus usually generates a withdrawal response, in general. For a quadrupedal animal, a withdrawal of one limb is not a big deal, but for a biped, a withdrawal reflex in the leg would put you at risk for falling over. A curling of the toes lifts the sole off the ground, presumably away from the noxious stimulus, while maintaining balance, long enough at any rate for you the consciously shift your weight and move your foot.

        Not exactly sure how or if the extensor Babinski is related, but, if you continue to apply the noxious stimulus (foul atheistic torturer of infants that you are), the extensor response usually turns into a withdrawal.

        The other interesting point to consider is that all the neurologic conditions (and there are quite a few) that generate the extensor Babinksi share one thing in common – there is a loss of cerebral cortical motor control/modulation of the spinal cord, either by an interruption of the connection (either in the brain, brainstem, or higher in the spinal cord), or by dysfunction/destruction of the motor cortex itself. That is, the extensor reflex is generated by the spinal cord near the level of the motor neurons that connect to the legs, while the flexor response is a result of a modulation of these spinal circuits by the higher centers in the motor cortex.

        Infants display the extensor Babinski because their motor cortex has not yet finished its development.

  8. Sili
    Posted July 16, 2009 at 2:41 pm | Permalink

    Interesting. I had a baby visiting last week. I’ll ask for a broom the next time I see her.

    • newenglandbob
      Posted July 16, 2009 at 2:48 pm | Permalink

      You only get a few months to try it out, Sili.

  9. Wes
    Posted July 16, 2009 at 3:18 pm | Permalink

    Yep. The “hanging a baby from a stick” experiment has actually been done, unsurprisingly by the same scientist of questionable ethics who performed the Baby Albert experiments. Here’s the pic:

    • Wes
      Posted July 16, 2009 at 3:21 pm | Permalink

      Oh, by the way…Sili, I hope the picture above satisfies your curiosity enough that you don’t perform the experiment yourself. ;)

  10. ritebrother
    Posted July 16, 2009 at 3:26 pm | Permalink

    My daughter was born just 14 days ago. The strength of her grip from day 1 was, and still is, remarkable. It’s honestly enough to surprise you, given how relatively flaccid the rest of her is at this stage. Her toe grip is also quite strong, and her toes respond quickly when you put your finger under them. An interesting hypothesis, this.

    • P Boshoff
      Posted March 5, 2012 at 3:58 pm | Permalink

      Lets put this ‘atheist’ versus creationist BS to rest. The fact is, as proven by now hundreds of hominid fossils, DNA and retained ‘primitive’ reflexes like the grasping reflex that we share a common ancestry with the higher pongids (apes). Besides is it not the same God who created both. So get over it!!!!!!!!

  11. nick nick bobick
    Posted July 16, 2009 at 6:18 pm | Permalink

    If any of you with babies and hairy chests (women excluded) want to experiment with just how powerful the prehensile toe grasp can be, try bouncing your child off your bare chest. I inadvertently did this once, and tears still come to my eyes when I recall the pain.

  12. Spirula
    Posted July 16, 2009 at 6:53 pm | Permalink

    Read and loved your book. I teach non-major biology classes and read as many of the these “for the general public” books regarding evolution that I can. I pass a list on to all students that may want to pursue this further. This book tops my list.

    This vestigial grasping behavior was one I had not seen written about before, and I think it is fascinating. I understand the explanation as to why it perpetuates in newborn humans, but is there any hypothesis as to why it vanishes when it does? Is there any correlation between neonatal primate develpmental behavior and the stage at which human neonates abandon this behavior?

  13. feelx
    Posted July 16, 2009 at 9:26 pm | Permalink

    I immediately went to youtube to find a baby dangling from something after I read this. I found this, lol, a little messed up but it only for a few seconds. http://www.youtube.com/watch?v=h9m1ghkTVPU

  14. theshortearedowl
    Posted July 16, 2009 at 9:51 pm | Permalink

    So where does the Babinski response fit into this? I thought in babies, stroking the sole of the foot made their toes curl up and away (hence its use as a sign of neurological damage in adults).

  15. Willy Brown Balls
    Posted July 17, 2009 at 6:51 am | Permalink

    Good ammo for the creationists, I like it.

  16. Posted July 17, 2009 at 8:02 am | Permalink

    The grasping reflex has become useless because of human cultural evolution. If humans suddenly reverted to a completely uncivilized state of hunter-gatherer lifestyle without any clothing & baby carriages, the grasping reflex of new born infants would have a very strong survival value. In that sense & unlike organs like the appendix, I would be hard pressed to call it vestigial.

    • BdN
      Posted July 17, 2009 at 12:50 pm | Permalink

      Baby primates grasp to their mother’s (and alloparents) hair. What would an infant in an “uncivilized” state grasp ?

      • amphiox
        Posted July 17, 2009 at 4:59 pm | Permalink

        There is no such thing as a “completely uncivilized state of hunter-gatherer lifestyle.”

        Genetic evidence from human body and hair lice suggest that clothing was invented at least 70 000 years ago, and there is evidence for the wearing of ornaments dating back 150 000 years ago, and I would bet fair money that the baby swaddle/sling predates the necklace.

        Even before we were H. sapiens, most likely carried our babies in our arms, if not by mom, then by aunt, big sister, or grandma, and maybe even dad.

        The only conceivable place a human infant’s grasp reflex could have been useful after our lineage lost our body hair would have been the mother’s long head hair. Show me evidence of hunter-gatherer infants clinging to their mothers by grabbing mom’s head hair (extant or fossil, it doesn’t matter), and I will consider the possibility that the grasp reflex is not vestigial in H. sapiens.

      • BdN
        Posted July 18, 2009 at 12:52 am | Permalink

        Since it wasn’t clear if you were responding to me or Aydin, I just wanted to make it clear that I agree with you on all accounts. That’s why I put “uncivilized” between quotation marks and my question was rhetorical : except for head hair, I don’t see what else the infant could have grasped. And I don’t think this would have happened very often. Unless you believe the aquatic ape hypothesis like this guy : “Babies’ clenching fists are simply grabbing mama’s long hair (another aquatic adaptation) for a tow while she’s foraging. ”

        http://www.uncommondescent.com/intelligent-design/darwinism-and-pop-culture-infant-grasping-reflex/#comment-326766

  17. jeff
    Posted July 17, 2009 at 10:40 am | Permalink

    is the appendix still considered vestigial?

    • amphiox
      Posted July 17, 2009 at 5:06 pm | Permalink

      Most certainly. Not only vestigial but detrimental. It is estimated that before the advent of modern surgery the lifetime risk of death from appendicitis was 1%. There is no conceivable benefit of the appendix that could possibly reach a magnitude that outweighs this risk, as on evolutionary terms, a 1% mortality risk is a huge, huge detriment.

      It has also been hypothesized that further shrinkage of the appendix would make appendicitis even more likely, because the smaller the diameter of the lumen, the higher the risk of it getting blocked, and thus natural selection cannot eliminate the appendix completely, as the intermediate step from current appendix to no appendix is detrimental. (Any intelligent designer, of course, could easily eliminate a no longer unnecessary and detrimental part like an appendix upon upgrading a design).

      On the other hand, there are people out there born with no appendix, and if this trait was heritable, one would presume, if appendectomy had never been invented (or forgotten in the future), the appendix-less trait would spread.

  18. Wes
    Posted July 17, 2009 at 11:39 am | Permalink

    Ugh… A trackback from UD? This thread is tainted…

  19. Reginald Selkirk
    Posted July 17, 2009 at 3:40 pm | Permalink

    The vestigial grasp of infants

    How dare you make such a rude crack about Mooney and Kirshenbaum.

  20. genecutter
    Posted July 17, 2009 at 4:17 pm | Permalink

    There are a number of other reflexes in infants as well that fade over time.

    http://www.keepkidshealthy.com/newborn/newborn_reflexes.html

  21. amphiox
    Posted July 17, 2009 at 5:11 pm | Permalink

    Almost all the “primitive” reflexes, like Babinski, grasp, suckle, etc, can reappear in adults as the result of neurologic pathology. In nearly all cases the proximal mechanism is a loss of cerebral cortical modulation/suppression of the reflex circuits present in lower brain and spinal cord centers.

    And the proximal mechanism for the existence of the reflexes in infants is the immaturity of the developing cerebral cortex.

  22. eddie
    Posted July 17, 2009 at 7:15 pm | Permalink

    Such a pity kids lose this trait. I remember my nephew holding on to his dad’s hands like that while taking his first steps.
    I’m surprised that no enterprising young cynic has mentioned recapitulation yet. So I will. How is this homo sapiens phylogeny trait related to the common ancestor trait?

  23. Michael K Gray
    Posted July 18, 2009 at 12:31 am | Permalink

    It is a sad, sad commentary on the state of the world when a new-born infant’s genitalia must be censored on a short science video clip.

  24. Posted July 18, 2009 at 9:05 am | Permalink

    Excellent choice of soundtrack.

  25. Posted July 19, 2009 at 7:51 am | Permalink

    This is my son Ben showing off his vestigial grasp.

    http://rationalskeptic.wordpress.com/2009/07/17/the-vestigial-grasp-of-infants-co-why-evolution-is-true/

  26. Posted July 20, 2009 at 12:43 am | Permalink

    This just in. Causality is always true! Science proves it.

    It depresses me every day to see more and more “blog garbage” being pushed as scientific fact. Don’t get me wrong… I love science… it’s just that stupid people are making science look dumb.

    I can show you a box of crayons, then a rainbow, and can show how both are multi-colored, but it doesn’t mean that the box of crayon generated the rainbow, nor that there is a box of crayons at the end of every rainbow, nor that the existence of rainbows proves that crayons exist.

    Two things in the world can have similarities, but it doesn’t mean one automatically proves a theory connected to another. Hydrogen is eerily similar to Helium, but that’s only because they’re made from the same stuff, with just a slight variation.

    It’s also similarly frustrating to see people compare the amount of similar DNA between two subjects. That’s like saying the odds of drawing a 10 of hearts from a deck of cards is precisely the same as drawing a 2 of clubs from a deck of cards… therefore, the 10 of hearts is really a 2 of clubs in disguise. No. There are just the same number of each card in a standard deck.

    • BdN
      Posted July 20, 2009 at 10:20 am | Permalink

      What exactly is your point ? We are note apes ? We don’t have vestigial traits ?

      • Posted July 20, 2009 at 12:01 pm | Permalink

        My point is… how does the vestigial grasp of infants have anything to do with evolution? The whole theory of evolution is being diluted by additional theories which have nothing to do with evolution.

      • BdN
        Posted July 20, 2009 at 1:28 pm | Permalink

        –“My point is… how does the vestigial grasp of infants have anything to do with evolution? ”

        Haven’t you read anything in the post and the subsequent thread ? I think it is pretty clear what it has to do with evolution.

        –“The whole theory of evolution is being diluted by additional theories which have nothing to do with evolution.”

        I think you mean “additional hypotheses”, not theories. And it HAS to do with evolution.

        –“Causality is always true! Science proves it.”

        I guess you’re trying to refer to “correlation is not causality” but fail at it. I would tend to think that causality is true. Otherwise, what would that even mean ?

        –“it’s just that stupid people are making science look dumb.”

        Who are you calling dumb ? Us ? Jerry A. Coyne ?

        –“I can show you a box of crayons, then a rainbow, and can show how both are multi-colored, but it doesn’t mean that the box of crayon generated the rainbow”

        probably not…

        “nor that there is a box of crayons at the end of every rainbow”

        granted!

        “nor that the existence of rainbows proves that crayons exist.”

        Maybe not per se, but it would a very good hint and would require some investigation to see how the two are related.

        –“Two things in the world can have similarities, but it doesn’t mean one automatically proves a theory connected to another. ”

        Ok, explain to me, since you seem to love science and the ToE, if you think that everything out there is only convergent evolution ? Is this what you are trying to say ?

        –“It’s also similarly frustrating to see people compare the amount of similar DNA between two subjects. That’s like saying the odds of drawing a 10 of hearts from a deck of cards is precisely the same as drawing a 2 of clubs from a deck of cards… therefore, the 10 of hearts is really a 2 of clubs in disguise. No. There are just the same number of each card in a standard deck.”

        WTF???

        So, you’re saying that the fact that my sister and me share a significant proportion of DNA is due to random chance ? The fact that humans share more with primates than with dolphins to to chance too ?

        –“There are just the same number of each card in a standard deck.”

        What does the standard deck stand for in your DNA false analogy ? The gene pool ? So, how different species draw from that deck ? Whatever you mean by that,it’s almost worse than some of the creationists already bad analogies…

      • Posted July 20, 2009 at 5:35 pm | Permalink

        By the way, it seems that some major assumptions are being made, which is why I think my words are being taken out of context. I am not a Creationist. I believe evolution is true. However, I think that people are ruining the theory of evolution by applying it in places that “seem” to fit much in the same way Fundamentalist Christians see “the hand of God” where a natural phenomenon is really taking place.

        I’m just trying to figure out the motivation for such enthusiasm. Most people don’t try to force others to believe things which are common sense. For instance, you don’t see people running around trying to explain how “gravity” is true. And yet, here is a site dedicated to trying to “prove” evolution. That implies that the author feels that there is a chance it might not be true, so he has made it his life’s work to try to convince others. The problem is, this only instills doubt in others. If scientists ran around trying to explain to people that gravity is a real phenomenon, people might wonder if there is some sort of “conspiracy” and maybe there is more to gravity than we all observe.

        If you believe in evolution as I do, then you shouldn’t need to discuss the topic in a manner where you are trying to convince others. When you do, you fall into the same trap that religious nuts fall into. Then, you start seeing connections where there are none. You see the “signs” that lead you to proving evolution even more than it was previously “proven” by the previous nuts. This cycle continues until there is so much doubt in the rest of the populace, that the entire group of “evolution believers” are dismissed as some sort of cult by the rest of the world. Except for, of course, everyone else who drank the same Kool-Aid.

        So a human baby grasps objects the same way as a baby chimp. Big deal. A baby chimp also has the same number of hands as a baby human, but you don’t see a bunch of so-called scientists running around excited about it.

        Ultimately, my concern is for the scientific community as a whole. It’s as if the only requirement to get a PhD these days is to prove you are passionate about an end-point of logic.

      • newenglandbob
        Posted July 20, 2009 at 6:29 pm | Permalink

        Now there is an example of messed up non-think.

        The first four paragraphs are just stupid. Why bother to teach math either? or history? or language? StarClips will just suspect them!

        “Ultimately, my concern is for the scientific community as a whole”

        The entire scientific community is likewise concerned about you too.

      • BdN
        Posted July 21, 2009 at 12:08 pm | Permalink

        –“By the way, it seems that some major assumptions are being made, which is why I think my words are being taken out of context. I am not a Creationist. I believe evolution is true.”

        I never said you were a creationist. I said quite the opposite : “Ok, explain to me, since you seem to love science and the ToE, if you think that everything out there is only convergent evolution ? Is this what you are trying to say ?”

        –“However, I think that people are ruining the theory of evolution by applying it in places that “seem” to fit much in the same way Fundamentalist Christians see “the hand of God” where a natural phenomenon is really taking place.”

        As much as you were confused over the causation/correlation and theory/hypothesis differences, you are here too. You seem to refer to the just-so stories scientists themselves denounce. But the question here is : is a particular structure or behaviour the result of an adaptation attributed to a specific selective pressure or is it a by-product, a spandrel, etc. The question is not, I repeat, is NOT whether it is the result of evolution or not : it IS the result of evolution because your whole darn body is. There ain’t no part of it that is not. Furthermore, you say that those saying it has to do with evolution are acting like religious people. This is a typical creationist argument. Failing to see that science can have an hypothesis further tested to see if the data supports it. In this case, it seems it does, even if it needs to be tested more thoroughly.

        –“I’m just trying to figure out the motivation for such enthusiasm. Most people don’t try to force others to believe things which are common sense. For instance, you don’t see people running around trying to explain how “gravity” is true.”

        Where do yo see “such enthusiasm”? Where do you see people “running around” ? This is a blog maintained by someone who writes about evolution. YOU are the one who came here to complain. He didn’t email it to you. Some people here are enthusiast because they hadn’t heard about it before and they find the matter interesting in itself. No different than people who rejoice over the new Michael Jackson song never released, or the new images from the moon-landing, or a breakthrough in medicine.

        –“For instance, you don’t see people running around trying to explain how “gravity” is true. And yet, here is a site dedicated to trying to “prove” evolution. [...]If you believe in evolution as I do, then you shouldn’t need to discuss the topic in a manner where you are trying to convince others”.

        The freakin’ difference is that there are no f*** religious organization saying that gravity is a myth and trying to ban it from education. It is dedicated to “prove” evolution because ignorant people aim to discredit a scientific theory.

        –“That implies that the author feels that there is a chance it might not be true, so he has made it his life’s work to try to convince others”.

        I don’t know how to address this one, you have such a twisted logic. Yeah, people try to convince others only when they fear they could be wrong… I guess you don’t discuss a lot. You are here, trying to convince us. Must be because you think you’re wrong. Therefore, I’m right. No need to argue anymore.

        –“So a human baby grasps objects the same way as a baby chimp. Big deal. A baby chimp also has the same number of hands as a baby human, but you don’t see a bunch of so-called scientists running around excited about it.”

        If you read scientific literature a little more often, you’d know that there are plenty other features over which scientists get “excited”. But you must not read it because you think they are “pseudo-scientists”.

        –“Ultimately, my concern is for the scientific community as a whole. It’s as if the only requirement to get a PhD these days is to prove you are passionate about an end-point of logic.”

        I don’t know what university you attend to, but obviously, it must be some sham like Liberty University. You’ve have obviously never done graduate studies yourself nor been near a Ph.d. student.

        By the way, you didn’t address any of my comments/questions. Must I conclude you didn’t read it because you are so deluded you thought everything had to do with me thinking you were a creationist ? Or do you lack reading skills ?

    • newenglandbob
      Posted July 20, 2009 at 12:56 pm | Permalink

      StareClips

      Your analogies are silly. If you want to make a point, then make it. Specifically what are you objecting to? Or is that just a general curmudgeonly crabbing?

      • Posted July 20, 2009 at 5:24 pm | Permalink

        I don’t think I can be any clearer. I suppose if you’re a religious freak and your mind cannot be changed, there isn’t much else I can say.

        How is this for an analogy. I can make a small car using only blue Legos. Then, I can make a small tree using only blue Legos. Then, someone can write an article saying that the tree must have evolved from the car (or the car must have evolved from the tree) because both have blue Legos. I say, maybe they are both similar because they are both made from the same building blocks.

      • newenglandbob
        Posted July 20, 2009 at 6:24 pm | Permalink

        Just as silly an analogy. Try plain language.

        Who is a religious freak whose mind cannot change? What does that have to do with vestigial traits of life or evolution?

        Is this another one of those ‘one hand clapping’ mind games?

      • Posted July 20, 2009 at 6:42 pm | Permalink

        I am using plain language. As plainly as I can say it, I disagree that the vestigial grasp of infants proves evolution. I’m not saying I disagree with evolution, nor am I disagreeing that infants have a vestigial grasp. I simply do not think that one proves the other. It’s ludicrous.

      • newenglandbob
        Posted July 20, 2009 at 8:33 pm | Permalink

        Then what is it, StarClips? What is your alternate hypothesis for the phenomenon? You can not just say I do not believe it and walk away. Why does it happen to every infant born? If it is not a legacy of earlier primates, then what is it? Caused by aliens from Alpha Centauri? Left over orders from a Pharaoh of Egypt?

      • Posted July 21, 2009 at 12:04 am | Permalink

        Usually, the simplest answers are the reality. It seems to me you’re trying to make something simple into something much more complicated.

        Baby humans have this capability for the same reason baby chimps have this capability. When you can explain why chimps can do this, you’ll already have your answer why humans can. Just because we are “civilized” now doesn’t mean we aren’t still just animals in the animal kingdom.

      • newenglandbob
        Posted July 21, 2009 at 5:22 am | Permalink

        OK, so your answer is that evolution explains it.

        It was already explained above why chimps do this.

      • BdN
        Posted July 21, 2009 at 12:09 pm | Permalink

        No, it’s not a better analogy. And as I said in my earlier post, if you had understood my critics of your previous ones, maybe you could have spared us with this one. You use another argument that look like a typical creationist one : if a watch as a watchmaker, how can an organism not have a creator. Here, you slightly shift it, cover it with confusing comparisons with Legos, but the argument is the same. Of course a freaking lego tree didn’t evolve from a lego car : they don’t f*** reproduce! Furthermore, you are using only one feature as if people were saying we evolved ONLY because of the vestigial grasp. It IS NOT THE CASE!!! But once you know, and accept, we evolved, it makes sense that it is the RESULT of evolution. Even then, going back to your crayola exemple, even if it was the only hint we had for evolution, it would not completely PROVE it but it would certainly be a really good hint since it is the only way it makes sense. Otherwise, there is no reason for having an organ with no purpose that other close species have and in which it is useful.

        Your example with legos is stupid because it would be as if scientists were claiming that humans came from lions because some have blond hair, or humans come from giraffe because we have a neck, or humans come from grasshoppers because we have eyes. If you ever find someone saying this, well, I’m gonna see the light and run to church. Or not, I guess.

        –“I say, maybe they are both similar because they are both made from the same building blocks.”

        Yeah? Well, WHY are they made from the same building blocks ? Which building blocks ? Why are some species are made from more similar building blocks than others ? And if some building blocks are found in related species, and not in others, maybe that’s BECAUSE THEY HAVE A COMMON ANCESTOR!!!

      • BdN
        Posted July 21, 2009 at 12:09 pm | Permalink

        –“I’m not saying I disagree with evolution, nor am I disagreeing that infants have a vestigial grasp. I simply do not think that one proves the other. It’s ludicrous.”

        Now your being really thick. How can you say in the same sentence that you believe it is “vestigial” but that it does not prove evolution ? This is rather illogical. Or you don’t know the meaning of vestigial. Which is another characteristic of creationists : using scientific words they don’t know the meaning of. Repeat after me : they are defined as vestigial BECAUSE of evolution. Otherwise, it would only be called baby grasp.

      • BdN
        Posted July 21, 2009 at 12:10 pm | Permalink

        As newenglandbob wrote : “your answer is that evolution explains it”. But along with reading skills, you lack logic too, as pointed out by your vestigial doesn’t equal evolution one.

        If, as you say so yourself, “baby humans have this capability for the same reason baby chimps have this capability” and “just because we are “civilized” now doesn’t mean we aren’t still just animals in the animal kingdom”, I really cannot understand how you don’t see how you contradict everything else you’ve said. Except if when you say we have this capability for the same reason as chimps, what you really mean is that it STILL serves the same purpose as in chimps. Obviously, it is not the case : we DON’T HAVE body hair! Except if you think that this reflex in chimps doesn’t serve the purpose of “young infants holding to their mothers’ body hair”. Then, you’re on your own. And if you wanna do this, you’re gonna have to do the same with every other vestigial structure. What a treat !

      • BdN
        Posted July 21, 2009 at 12:10 pm | Permalink

        One final word : your last message was deleted. Probably because it included an insult toward newenglandbob, insult that you could apply to yourself. But I’ll cite the “neutral” part because it is relevant here :

        “So then clearly, while everyone else evolved from chimps,”

        Once again, you show how you don’t know what you’re talking about. We didn’t evolve from chimps : we both had a COMMON ANCESTOR. Anyways, going back to my previous post : if we “evolved from chimps” and the vestigial structure serves the same purpose in both, as you say yourself, how can you not see how it is a product of evolution ? Words fail me…

        So to synthesize all this :

        even if you claim to not be a creationist, you sound highly suspicious because you use many creationist-like arguments. That or you are scientifically illiterate and illogic.

        Have a nice day!

  27. Posted July 21, 2009 at 1:24 pm | Permalink

    The reason I do not answer every question is because it seems that everyone else here thinks I am the center of the Universe. Alas, I am not. So, while I would love to answer everyone’s questions, I do not have the time to do so. I only have the time to take part in a discussion. A discussion everyone was taking part in. And since my opinion differed from yours, suddenly I became the center of the Universe for you. For that, I apologize. Next time I’ll try to make sure my opinion matches yours.

    My original point had nothing to do with the purpose of vestigial grasps or whether or not scientists are “running around” or just acting casually. I guess I am just generally disappointed with the fact that so much energy is being poured into scientific works without any passion at all.

    Imagine, for instance, if there were a blog dedicated to Mathematics. On Wednesday, there was a blog post which talked about how 2+3 is equal to 5. The proof is shown, a discussion takes place, people chime in with their opinions on the matter, maybe a joke or two… then, on Thursday, a new blog post half a page long discusses how 5+7 is equal to 12. Once again, a proof is shown, a discussion takes place, people chime in with their opinions, maybe a joke or two.

    At some point, wouldn’t it be novel to contribute to the scientific community information and findings which are not already obvious? i.e., if you say that our entire bodies are already 100% a result of evolution, then how many body parts and muscle functions are going to be analyzed by various blog posts before anyone realizes how much energy is being wasted re-stating the obvious?

    • NewEnglandBob
      Posted July 21, 2009 at 1:39 pm | Permalink

      I am just generally disappointed with the fact that so much energy is being poured into scientific works without any passion at all.

      Now that is one incredibly stupid statement. You accuse hundreds of thousands of scientists of something with no evidence except your ‘beliefs.

      Once again, StairClips, your thinking is muddled, your thoughts are ill formed, and your analogies are insipid.

      When your silly statements are ripped apart and stomped upon as they all have been here you then resort to either ad hominem attacks that had to be delete or you resort to saying you have no time to answer the reasoned responses.

      Only YOU think that you are the center of the universe. I guess you are a legend in your own (twisted) mind.

  28. Posted July 23, 2009 at 12:51 am | Permalink

    Quite interesting concept…

  29. Posted January 17, 2010 at 11:04 pm | Permalink

    As a doctor, and the mother of an infant, I found this really interesting. I’ve also noticed that my 7 month old uses her feet to manipulate objects and to hold onto things while she uses her hands to play with them when lying on her back. I’m not sure what chimps do, but I’m pretty sure they use their feet for much more than walking!

  30. Johnny Bourdeaux
    Posted December 28, 2010 at 9:08 pm | Permalink

    I was having a conversation with my girlfriend (who is somewhat theistic evolutionist or creationist, depends on a hair day) and I told him about infant grasp reflex. So I googled and found this blog post, interesting!

    Speaking of some other vestigial traits, I think it’s worth noting that aforementioned 1% appendicitis death rate probably has not been a big problem in our evolutionary history, judged by african genetic heritage.

    Nobel Price Winner Albert Schweitzer spent 41 years as a physician in Gabon, Africa and there were fewer than 3 cases of appendicitis per year. Similar interesting reports have been published in New England Journal of Medicine and JAMA for good measure. Even more interestingly, appendicitis has been reported as one of the first diseases of civilization to occur in indigenous people after exposure to western lifestyle and food products.

    Indigenous people overall have patterns of illness very different from Western civilization. Yet they rapidly develop diseases once exposed to Western foods and lifestyles – much more rapidly than typical westerners with similar exposure.

    So instead of considering appendicitis as a ‘fault’ of evolution, I’d consider it more probably as a fault of cultural evolution. Similar arguments probably work for many cancers, heart disease, diabetes and certain opportunistic infections.


11 Trackbacks/Pingbacks

  1. [...] not asking you to hang a baby by a broomstick, [...]

  2. [...] A correspondent posed me this interesting question about the infant grasping reflex: Incidentally, what do the ID and the Evolution-is-limited-in-scope (Behe, et all) do with data like this: [...]

  3. [...] saw this at Jerry Coyne’s blog. Vestigial structures (click here for wiki) are fascinating. Goosebumps, hiccups, male nipples and [...]

  4. [...] the rest of the article in WEIT. [...]

  5. [...] the world is a pendulum. A great post on Why Evolution is True about the vestigial grasp observed in human infants was countered by a silly post on Uncommon [...]

  6. [...] had written to say that some Darwinist somewhere was fronting the ability of human infants to hang on a couple of minutes as evidence of common descent with [...]

  7. [...] The vestigial grasp of infants « Why Evolution Is TrueIt is estimated that before the advent of modern surgery the lifetime risk of death from appendicitis was 1%. There is no conceivable benefit of the appendix that could possibly reach a magnitude that outweighs this risk, … [...]

  8. [...] The vestigial grasp of infants « Why Evolution Is True Share [...]

  9. [...] world-view What purpose does baby have for such a strong reflex? other than the obvious. http://whyevolutionistrue.wordpress….sp-of-infants/ Reply With [...]

  10. [...] and normally occurs by four months. Some commentators see baby grasping within the scope of a larger issue, but we are just happy that Arya is on track with her motor skills. Since she just learned how to [...]

  11. […] Palmar Grasp and Plantar Reflex […]

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