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From: hua@cmu-cs-edu1.ARPA (Ernest Hua)
Newsgroups: net.origins
Subject: re: Innocent Question
Message-ID: <283@cmu-cs-edu1.ARPA>
Date: Wed, 8-May-85 23:10:53 EDT
Article-I.D.: cmu-cs-e.283
Posted: Wed May  8 23:10:53 1985
Date-Received: Fri, 10-May-85 22:10:20 EDT
Organization: Carnegie-Mellon University, CS/RI
Lines: 36

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> From: berger@aecom.UUCP
> 
> This is an innocent question, not intended to be an attack.
> So give me an answer, not a defence.
> 
> I was just wonderin'... If evolution happened in abrupt
> changes, wouldn't two animals have to undergo the same
> (or a similar) change? I mean, if in each step the new
> species can't breed with the old, we would need two of
> the new species in order to get something started. 
> What's the chance that there are two animals, 1 male and
> female, within the general vicinity (close enough so that
> they could find eachother), undergo the same drastic change
> in the same generation?

Good question.  I assume that you are refering to punctuated biological
evolution.  This idea does not call for speciation at an instant.  It
merely says that gradual changes do occur, but in rapid succession such
that the intermediates between stable forms are few.  The changes still
must be gradual so that breeding and proliferation may occur.  The only
real difference between gradualism and punctualism (I wonder if this is
a valid name for it; anyone know?) is that the changes occur in narrow
groups rather than in uniform spacing (on a time line).  Thus, the forms
that occur in great numbers in the fossils are likely to be stable forms,
and the forms that occur in relatively few numbers are likely to be
unstable "transitional" forms.  (That is quoted because every form can
be considered a transitional form.  The usage here refers to forms that
are intermediates between stable forms.)
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Live long and prosper, but don't evolve;
you might get some people very angry!

Keebler { hua@cmu-cs-gandalf.arpa }