Model Organisms

L.A. Moran lamoran at gpu.utcc.utoronto.ca
Tue Apr 29 18:51:40 EST 1997

In article <5k398r$cfc at ruacad.runet.edu>,
Richard M Kliman <rkliman at runet.edu> wrote:
>In article <E95qDo.Dvs at gpu.utcc.utoronto.ca>,
>L.A. Moran <lamoran at gpu.utcc.utoronto.ca> wrote:
>>I appreciate the point that you are trying to make but perhaps it would be
>>best to remember the context. Someone wanted to knw if there were any
>>organisms that were more primitive than Drosphila but less primitive than
>>C. elegans. Why? Because he was hoping to isolate a C. elegans gene using
>>a human probe and was looking for an "intermediate" model organism. Do you
>>think that this is a reasonable experiment? Is it consistant with your
>>understanding of evolution. (I sure hope not or I have seriously misjudged
>>you!)  (-: 
>Don't get me wrong.  I understand the nature of phylogenetic 
>relationships.  However, what the researcher was asking for was not 
>unreasonable.  I'm going to trust that the researcher was using the term 
>"primitive" in a sense that we can understand even if we disagree with 
>its use here.  The researcher was looking for a model organism that 
>shares a less recent common ancestor with humans than does Drosophila, 
>yet shares a more recent common ancestor with humans than does C. 
>elegans.  Now, this was not stated explicitly, but I see no reason to 
>assume that the guy is ignorant with regard to evolution.  My suggestion 
>that he consider a mollusc was made with the assumption that he 
>understood evolution, but lacked an appreciation for our jargon.  I hope 
>that this exchange will not deter others from asking readers of this 
>newgroup for future assistance.

Molluscs are definitely out. They are proterostomes, just like insects.
In fact, there may not be an organism that meets your definition.

>And unless there's been a change that I don't know about, it's reasonable 
>to assume a priori that the Aplysia gene will be more similar to the 
>human gene than either is to the C. elegans gene.  The experimental 
>approach, at least on the surface, strikes me as rational.

I'm afraid I don't agree. Could you please explain how you could clone the
C. elegans gene using Aplysia as an intermediate? There seem to have been
some changes to evolution that you don't know about.  (-:

Larry Moran

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