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From: werner@aecom.UUCP
Newsgroups: sci.bio
Subject: Re: The Human Brain
Message-ID: <1301@aecom.YU.EDU>
Date: Tue, 1-Sep-87 10:23:50 EDT
Article-I.D.: aecom.1301
Posted: Tue Sep  1 10:23:50 1987
Date-Received: Thu, 3-Sep-87 06:40:17 EDT
References: <1041@ttidca.TTI.COM> <2851@phri.UUCP> <2172@xanth.UUCP> <3835@cit-vax.Caltech.Edu>
Organization: Albert Einstein Coll. of Med., NY
Lines: 28
Keywords: The advantages of redundancy.

In article <3835@cit-vax.Caltech.Edu>, palmer@tybalt.caltech.edu (David Palmer) writes:
> There are also poeple with hollow brains, hydrocephalics whose brain is
> just a thin veneer over a bubble of cerebro-spinal fluid.  Many of these
> people are normal or above normal in intelligence, even though they have
> only 5% (!!!) of the normal brain mass.
> 
> Are there any theories out there about why the rest of us need so much
> brain when these people get by with so little? is it just because of the
> advantages that redundancy gives us?
> 

	Once again, the answer to that question is "Yes."
	We forget about it today in this age of modern medicine, but most
of the "common" diseases of childhood (measles, pertussis, bacterial
meningitis, any disease causing dehydration, high fever, or anoxia)
can and will result in brain damage.
	Most of these diseases are not seen in the western world, hence
our myopic ignorance of them. But since evolution has to work on the
reproductive population, "redundant" brain mass would be selected so
as to ensure an adequate amount of surviving brain tissue by the time a 
person reaches puberty (which is about age 20 on a subsistence diet, 
but much lower on a western high protein diet.)
	Any explanation which ignores this fact is just pure errant pedantry.
-- 
	        Craig Werner   (future MD/PhD, 3 years down, 4 to go)
	     werner@aecom.YU.EDU -- Albert Einstein College of Medicine
              (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517)
     "The proper delivery of medical care is to do as much Nothing as possible"