preston@valid.UUCP (05/21/86)
Craig Werner writes: > If having excess neurons allows half to be destroyed in childhood > without early dementia, then it provides a clear evolutionary advantage. This is an interesting topic to me, not for the evolution vs. creationism aspect of it, but because we take it for granted that intelligence is always a good thing, whereas it may not be. By Werner's reasoning we ought to have two or three brains, just in case. (Why keep all the stuff in one place?) I wonder if there aren't cases where having all those extra nerves is just asking for trouble. It would seem to me (naively) that nerve paths provide a sort of interstate highway map for some kinds of viruses to follow, and the richer a nervous system you have the more inroads they can find. (I'm thinking of herpesviruses; I had shingles about ten years ago.) I seem to remember hearing about some research in which someone showed that intelligence is selected against in rats. Anybody know about this? (Some people will probably suggest it is also selected against where my family comes from.) There are certainly constraints against brain size, e.g. an infant's brain at birth is limited in size by the size of the birth canal. Stephen Jay Gould says one reason why the human baby is so helpless when born is that the human infant is a sort of fetus that got out of the womb too early. If it stayed in until it was as developed as its mammalian counterparts it could not be born without killing its mother. Anyway, there is a price to be paid for all this excess brain size. As for the 5%-95% argument, I don't take it too seriously. If somebody came to me and said, `You're only using 5% of your brain, so let us scoop out the other 95%,' I'd probably decline the offer. I may be only using 5%, but I want ALL of it. (In fact, if you have any extra lying around, please send it to me.) -- -Preston Gardner (..!{hplabs,amd,pyramid,ihnp4}!pesnta!valid!preston)