Subject: Whale Evolution

Courtney Stirling Casey (stirling@gsosun1.gso.uri.edu)
Sat, 8 Nov 1997 20:29:03 -0500 (EST)

---------- Forwarded message ----------
Date: Sat, 8 Nov 97 20:27:15 EST
From: Mail Delivery Subsystem <Mailer-Daemon@gsosun1.gso.uri.edu>
To: stirling@gsosun1.gso.uri.edu
Subject: Returned mail: Host unknown

   ----- Transcript of session follows -----
<<< RCPT TO:<Rhiannia@aol.com>
<<< RCPT TO:<pita@whale.wheelock.edu>
<<< RCPT TO:<beal.49@osu.edu>
<<< RCPT TO:<ask@wheelock.whale.edu>
<<< DATA
<<< QUIT
421 Host wheelock.whale.edu not found for mailer ddn.
550 <ask@wheelock.whale.edu>... Host unknown

   ----- Unsent message follows -----
Return-Path: <stirling@gsosun1.gso.uri.edu>
Received: from localhost by gsosun1.gso.uri.edu (4.1/SMI-4.1)
	id AA05368; Sat, 8 Nov 97 20:27:15 EST
Date: Sat, 8 Nov 1997 20:27:15 -0500 (EST)
From: Courtney Stirling Casey <stirling@gsosun1.gso.uri.edu>
X-Sender: stirling@gsosun1
To: Rhiannia@aol.com
Cc: pita@whale.wheelock.edu, beal.49@osu.edu, ask@wheelock.whale.edu
Subject: Teeth vs. Baleen-evolution of
In-Reply-To: <971107233555_1962039073@mrin58.mail.aol.com>
Message-Id: <Pine.SUN.3.95.971108201645.5325A-100000@gsosun1>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

Matt,
	While I do not KNOW the answer to that question I can speculate
from my knowledge of how evolutionary pressures exert themselves on
species.  I would think that at some point some genetic mutation or blip
in the normal translation-transcription process coded for some non-teeth
type feeding apparatus.  The indivudual in which this blip happened
perhaps lived longer and had more offspring than the indivuduals in which
the 'normal'feeding apparatus was coded for.  At this same time there were
many species competing for the 'large chunk' type prey.  So, those
indivudual who had the non-teeth feeding apparatus then had the advantage
of being able to feed on non-large chunk type food.  Does this make
sense to you?  So, over evolutionary time, the whales that had and then
perfected the non-teeth (or baleen) feeding apparatus had an advantage and
managed to exploit a food source that other large marine organisms were
not able to take advantage of.  I hope that this helps.  I would be more
than happy to answer more questions along this line if you have them.  I
should also restate that this MAY NOT be how baleen diverged from teeth.
But, it is one possibility.  Folks do think that most morphological
variation is the result of genetic 'blips" (as I call them) that result
in increased fitness.


Good luck in this line of thinking!
Courtney

On Fri, 7 Nov 1997 Rhiannia@aol.com wrote:

> Date: Fri, 7 Nov 1997 23:35:55 -0500 (EST)
> From: Rhiannia@aol.com
> To: stirling@gsosun1.gso.uri.edu, pita@whale.wheelock.edu
> Cc: beal.49@osu.edu
> Subject: Teeth vs. Baleen
> 
> I am an undergrad at Ohio State University.  My animal diversity class is
> discussing several topics dealing with whales.  I wanted to know if you could
> provide some light upon a question I have.  Evolutionarily, why would whales
> develop baleen to catch plankton for food when teeth would allow the whale to
> take in larger chunks of food for nutrition?  In the ancient past didn't most
> large sea organisms have teeth due to predacious behavior?  I thought it
> would be much easier for these large animals to obtain their nutritional
> needs by catching larger prey items.  Do you have any information that could
> throw some light on the subject?
>                                                                     Matt Beal
>   beal.49@osu.edu
>