Pharyngula

Humans are very strange animals

I mentioned that cringe-inducing hemipenectomy that some spiders do…well, Stan Schwarz had to one-up me and sent a link to an image of an example of full genital splitting (if you click that link, you’re probably safe; it’s a very tiny thumbnail image. Click on that, though, and all bets are off). I have no idea why any human being would want to do that—it looks like a very creepy meat butterfly in the guy’s crotch. If that description alone grosses you out, you definitely don’t want to click on that link. Move along, move along.

Comments

  1. #1 thwaite
    June 29, 2006

    Caledonian, I agree that (in principle) we could find some brain module we’re looking for concerned with maximizing sexual encounters – sex is fun (via some neuro-physiological wiring) as Diamond discusses. As to WHY we’re expecting to find such a module – that’d be the evolutionary adaptive value part of the explanation, and equally important.

    “How” and “why” are both parts of teleological analyses suitable for functional systems. For living systems, the How questions include
    * Cause – the immediate physiology and stimuli
    * Development – the physiological changes due specifically to maturation
    and the Why questions include
    * Evolution – the semi-random history leading to this individual
    * Function – the adaptive values favoring specific traits
    - you’ll note that these fall into a nifty mnemonic CD+EF, useful especially when dealing with analyses of Animal Behaviors (so AB=CD+EF)

    Teleological analyses go back to Aristotle. I’m familiar with them through reading the animal behaviorist Niko Tinbergen (who was Richard Dawkins’ advisor).

    I’m still bemused at any possible function for hemipenectomy. As mythusmage notes it’s probably not heritable. Best chalk it up to some very random history if not disorder.

  2. #2 Betty Cocker
    June 29, 2006

    Thwaite and Dave,

    I think your idea of a direct genetic link to reproductive quantity in today’s world for humans is likely going nowhere.
    Humans as a species are outstandingly successful, possibly too much so for our own long-term good.
    If you trace the reasons for this, much of it comes from technology. When you trace the roots of that you come back to our ability to communicate and pass on ideas.
    Symbolic language was a pivotal event in our evolution. But something strange happened. Once we could communicate symbolically, we ourselves became both the generators of, and the environment for, blocks of information that Dawkins called memes.
    Now these control much of our behavior – religion, science and culture being parts of this information system. Much of our behavior is memetically rather than genetically controlled. This explains a lot of those behaviors that clearly don’t help us genetically (suicide bombing, or self mutilation, for example). Since memes mainly demand that we have big brains and can communicate symbolically, identical twins or cloned humans could come up with completely different behaviors with regard to reproduction. Even someone with very little sex drive, can with suitable cultural influence produce many children. So I doubt you can look at this in a basic biological way, once the equipment is in place. Humans are indeed a very strange species.

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