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From: mrh@cybvax0.UUCP (Mike Huybensz)
Newsgroups: net.origins
Subject: Re: Beast of Burden
Message-ID: <510@cybvax0.UUCP>
Date: Mon, 29-Apr-85 11:25:37 EDT
Article-I.D.: cybvax0.510
Posted: Mon Apr 29 11:25:37 1985
Date-Received: Wed, 1-May-85 05:43:43 EDT
References: <948@uwmacc.UUCP> <491@cybvax0.UUCP> <977@uwmacc.UUCP>
Reply-To: mrh@cybvax0.UUCP (Mike Huybensz)
Distribution: net
Organization: Cybermation, Inc., Cambridge, MA
Lines: 27

> >> [Paul DuBois] 
> >> I didn't forget.  But just how likely does it seem to you that two
> >> independent lines of development from a smooth-brained ancestor with no
> >> convolutions, to two different animals with convolutions, will result
> >> in EXACTLY the same number of fissures, and that all 14 will be in
> >> corresponding locations?  I confess skepticism (that healthy quality so
> >> highly touted).
> 
> > [Mike Huybensz]
> > The neocortex of all mammals is convoluted.  Which smooth-brained ancestor
> > are you talking about?  And what makes you think it was smooth brained?
> 
> [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 think endocranial casts will show convolutions and fissures of the
brain.  Look at the inside of a human skull: it is smooth on top.

I may get around to checking this one out....
-- 

Mike Huybensz		...decvax!genrad!mit-eddie!cybvax0!mrh