Tuesday, December 25, 2007

Is your brain full of anachronistic junk?

According to David Linden, author of The Accidental Mind,
David Linden's book "The Accidental Mind" explores the thesis that the human brain is a hotchpotch of suboptimal components gathered together by the vagaries of

Even the Nature reviewer, Georg Striedter, baulks at the idea,
"More difficult to show is that the use of pre-existing parts imposes functional constraints or 'bad design'." Also: "Linden is right to stress that brains evolved, but hasty to conclude that they are flawed in their design. What we do know, and what The Accidental Mind helps us to realize, is that the human brain is not designed as many have imagined.

How does reviewer Striedter know that the brain is not designed? Actually, he doesn't; he assumes that as a starting point. The fact that even HE appears to doubt the "accidental mind" thesis should undermine his certainty, but of course it doesn't.

Anyway, British physicist David Tyler disagrees:
Books like this, and reviews like this, demonstrate yet again how unlevel the playing field is in contemporary science journals. Contributions that deny design, meaning and intelligent agency are given space, whereas proponents of design, meaning and intelligent agency are excluded (and told they have abandoned the scientific method). This is a good example of the tendency for "our minds to distort reality and to act foolishly"!

I haven't yet got a chance to read the book, but I expect that I will not find Linden's thesis persuasive, for two key reasons: Our universe itself shows enormous evidence of fine tuning, a fact admitted by so many great scientists that the speculation that there are arbitrarily large numbers of other, flopped universes is considered the only serious alternative. So there is no strong reason, apart from ideology, to doubt that life forms might also show evidence of design.

Second, if there were really a great deal of anachronistic junk in our brains (as opposed to systems that have changed their functions, for example, or systems that use workarounds), neurological disorders would be far more common than they actually are.

While we are here: There are several platforms in our brains, the newer built on the older, but it's best to be cautious of theses that attempt to derive major truths from this fact.

For example, years ago, I was willing to accept the idea that alligators could not feel emotion in the mammalian sense. Canada, after all, is not generously endowed with reptiles, so I don't deal with them on an everyday basis, as I deal with mammals and birds. But then I ran into a man who knew more about alligators than I would have thought possible. His job was tagging them for conservation research projects, and here's how he did it:
Using a headlight on my head, I can see the eye shine of an alligator several hundred meters on a dark night. I then call the alligator for a closer look by mimicking the alarm call of a baby alligator and make splashing sounds with my hand in the water. The sound is irresistible and the alligator swims toward the boat. If I am working in a new area I can usually call about 80% of the alligators close enough for their heads to hit the boat.
No one says alligators are especially clever, but it may be that they use the reptilian brain for things for which the mammal uses the mammalian brain, and that the differences are not as great as are sometimes thought. Anyway, I have become cautious abut reptile brain", "dinosaur brain", and "kludge brain" theses.

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