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From: draves@harvard.ARPA (Richard Draves)
Newsgroups: net.origins
Subject: Re: Beast of Burden
Message-ID: <79@harvard.ARPA>
Date: Thu, 25-Apr-85 16:53:52 EST
Article-I.D.: harvard.79
Posted: Thu Apr 25 16:53:52 1985
Date-Received: Sat, 27-Apr-85 03:14:07 EST
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Organization: Aiken Computation Laboratory, Harvard
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> [Paul DuBois] 
> A reasonable question.  The information comes from a study of
> endocranial casts obtained from fossil skulls.  Early horses were
> smooth-brained.  More information may be obtained from:
> 
> 	Tilly Edinger, "Evolution of the Horse Brain".
> 	Geol Soc Amer Memoir, 25, 16 Feb 1948.

I don't know much biochemistry, so take this hypothesis with
a grain of salt.  Much of the genetic code is never expressed.
Some mutation in an early horse resulted in the genetic material
that produces convoluted brains being "hidden".  Later, another
mutation resulted in the reappearance of this trait.

Rich
-- 

	"a picture in the head is a gory murder in an art gallery"

					-- Stephen Kosslyn