Home » Intelligent Design » Common ancestry: More on the infant grasping reflex

Common ancestry: More on the infant grasping reflex

A while back, I wrote to a correspondent about the infant grasping reflex.

He 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 chimpanzees, and wondered how I could possibly deal with this evidence. (Well, I guess it would buy the human infant a couple of minutes of life, right? Not an attractive prospect, in my view. Better look elsewhere for human survival.)

Look, I do not have a problem with common descent, until its advocates get up on their hind legs and start arguing for it. One gets some of the worst arguments in the world, fronted by vast academic paraphernalia – and, very often, implied threats if one doesn’t agree thrown in.

Now, the story in question raised the question of what counts as evidence of common descent.

As a teenager, (I married when I was 20), I paid my way through school, net of scholarships, by looking after babies, toddlers, and other small children.

I am no expert, but I know a bit about such creatures. As I explained to my correspondent, the human infant does not use the grasp reflex primarily for hanging on to Mom, but primarily for stuffing any grasped object into its mouth.

This makes sense from the human infant’s perspective, of course. While the child can recognize mom’s voice before birth, her voice is mainly a source of reassurance, not information.

Eyesight is a very great benefit for a child – once he can distinguish the boundaries of one item from another. The first thing most kids learn to distinguish is smiles, which they begin to copy, typically around 6 to 8 weeks of age. Experts differ as to whether the child really reciprocates affection or is merely copying a routine.

I have no learning to justify entering this controversy, so let me note only note that, whatever may be the case with the child, millennia of humans have seen the results and said., “See! He knows I am his dad and I am so very proud of him!” or “She’s my little princess! Just see how she smiles at me!” So the human race goes on.

It is curious that – if some expert opinion is true – the child is programmed to act like he knows what is happening before he does, because adults notice and react favourably.

Anyway , I told my correspondent,

Claims about common ancestry should be founded strictly on genome mapping, NOT on behaviour.

Behaviour is simply NOT a reliable guide. Closely related life forms can have different behaviour – and life forms too distantly related to shed any light on each other can have similar behaviour because the behaviour is a necessary adaptation for the life they must pursue.

For example, opossums and koalas have offspring that cling to their mothers, but because they are marsupials, no one suggests that it demonstrates anything about close common ancestry woith humans or other placental mammals.

Accounts of similar behaviour may feel good to the already convinced, but, as an enterprise in the serious study of evolution, this sort of thing is doomed to failure.

If the human and chimpanzee genomes overlap about 70-76% (a reasonable figure – forget the 98-99% chimpanzee hype), that suggests common ancestry as a reasonable probability, given other similarities. Also, there are apparent “errors” (e.g. Vitamin C pseudogene) that appear in both genomes, which adds strength to the argument. For example, ID advocate Mike Behe talks about the Vitamin C pseudogene in Edge of Evolution, as evidence for common ancestry.

I don’t know. I just follow the story, unlike the pundits who KNOW.

See also: Darwinism and popular culture: Well, aren’t we all 30 per cent banana anyway?

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10 Responses to Common ancestry: More on the infant grasping reflex

  1. Denyse,

    Great post! However, note that Cornelius Hunter has shredded the vitamin C pseudogene argument for common descent many times. Here’s the latest iteration, dated July 11:

    http://darwins-god.blogspot.co.....llins.html

  2. Childhood of man can’t be compared to chimpanzee. According Portmann human children are born one year before they should be. Human is so socialized that he needs to develop also in “social uterus” in order to be able to live in society.
    Learning language is another thing neodarwinists do not see in correct way. It creates great gap between human infant and animals.

    http://cadra.wordpress.com/

  3. I am no expert, but I know a bit about such creatures. As I explained to my correspondent, the human infant does not use the grasp reflex primarily for hanging on to Mom, but primarily for stuffing any grasped object into its mouth.

    A trait we share with as disparate relatives as pandas, monkeys, and chimps too… Oh wait, haven’t I seem them hanging on to Mom?

    Thinking it over, I wonder if they would even live long enough to get to sucking their own thumb if they didn’t…

  4. Slightly on-topic… I have found evidence that Nirvana and Rick Astley have a common ancestry.

    Their DNA sequences line up almost perfectly.

  5. It is just a developmental trait guys. As the child gets older the grasping reflex slowly becomes more controlled as the child develops cortical inhibition in the brainstem circuits. Look it up.

    On the topic of common descent, however, I recently learned a fascinating fact from some researchers at Harvard. Humans have a ligment that attaches the head to the shoulders called the nuchal ligament. Other mammals such as horses, dogs, and cheetahs also share this ligament. What is interesting is that chimpanzees and australopithecines (Lucy), do not.

    I realize that chimpanzees and australopithecines have been discarded by Darwinists as ancestors of humans – but still it is an interesting fact.

  6. There are a few more baby reflexes
    http://www.keepkidshealthy.com.....lexes.html
    Here’s a interesting one:
    Stepping/Walking

    Most parents are surprised by this reflex. If you hold your baby under his arms, support his head, and allow his feet to touch a flat surface, he will appear to take steps and walk. This reflex usually disappears by 2-3 months, until it reappears as he learns to walk at around 10-15 months.

  7. 7
    CannuckianYankee

    The Darwinian Story of the Grasping Reflex:

    In the olden-olden-way-beyond-recorded-history-days, infants grasped their mothers’ hair real tight so they wouldn’t fall off her shoulder when mother was running from the charging woolly mammoth or other beasts of the field.

    They did this because mothers hadn’t yet evolved the nurturing instinct we see in the typical soccer mom of the 21st century, and the instinct to design infant back harnesses had not yet evolved. Also, infants at the time hadn’t yet developed the “oh horror! gasp and run” instinct we see in infants of the 21st Century at first sight of purple singing dinosaurs on the telly on Saturday mornings, requiring mothers to quickly grab Junior and run.

    At the time, evolution compensated for the dangerous tendency of infants to lose their grip of mommy’s hair when running from the woolly mammoth or other beasts of the field, by giving mommy more leg hair and a “god no, don’t shave legs” instinct (which eventually lost out to the “need to attract bald men by shaving legs” instinct), thus softening the infant’s fall. And this is evidence of evolution in action. :)

  8. the human infant does not use the grasp reflex primarily for hanging on to Mom, but primarily for stuffing any grasped object into its mouth.

    I think brachiation is the key word!

    The grasping reflex obviously is a relic from “our” brachiating past. A characteristic of the brachiating lifestyle is the requirement to survive as a suckling before the time is ripe for stuffing grasped objects into mouth.

    We are descended from brachiators, so what is O’Leary’s point?

  9. I see “pull ups” is the key word.
    http://en.wikipedia.org/wiki/Pull-up_(exercise)
    I see these reflexes a link to the babies future as the walking reflex while others seems to try linking everything to some unknown past. I find my grip is very useful in my every day life.

  10. I see these reflexes a link to the babies future as the walking reflex while others seems to try linking everything to some unknown past. I find my grip is very useful in my every day life.

    Happened to see a orangutan birth in a BBC documentary yesterday. Guess what the baby did with his hands?

    Nobody ‘links everything to some unknown past.’ The observation of how orangutans actually live and how they are able to survive as a brachiating species is there for all to observe for themselves. I think orangutan babies first of all need a firm grasp in order to survive until they they can let go of their mother.

    It shouldn’t be that hard to realize that that’s the ‘why’ of the gripping reflex. Which doesn’t seem to have much to do with a ‘walking reflex’, especially for a knuckle walker.

    Anyway, it is well within reasonable, consistent evolutionary theory to attribute our gripping reflex to descent from a brachiating ancestor in common with orangutans.

    Humans are apparently a brachiator adapted for bipedalism.

    All I am saying is how it looks, the observations are what they are, and we are free to attribute our observations to ID, evolution or the FSM.

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