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Re: Evolution programs (was: Reevolving bones)



Jonathan R. Wagner writes;

>        To do what George wants seems to me to require modeling the entire
>process of molecular evolution, expression of genotype in the phenotype
>(including developmental effects), the expression of mutation in the
>phenotype, the expression (or lack thereof) of anatomical features in the
>skeletal structure, a full ecosystem with environmental constraints and
>adaptive zones, lots of different selection pressures and their sources, and
>about fifty other catchy buzz phrases.

I think you may be misinterpreting the nature of the experiment that George has 
suggested.  To take a cue from Stan's last posting, assume that cladistics 
operates under the same rules as any statistical analysis, where the more data 
points you include, the better the results.  Let's say that we are able to 
discern some 200 or so separate character traits.  Run all these traits into 
the computer (or do it by hand if you enjoy the torture ;^), and see what 
results you get.  In theory, using this many data points would overwhelm any 
instances of convergent evolution.

As a follow-up, have a few non-cladist types do the same analysis by hand, 
using their favorite methods.  How closely would the results be to each other?  
If they are different, who do we believe: the computer or the human?

One further question:  Does cladistics take geography into account?  I'm not 
talking about terrain or climate, but where on the Earth each of the genera is 
found?  Could a cladistic analysis claim that animals on separate continents 
are more closely related than those on the same continent (and is this 
feasable)?

Of course, I wonder if we can completely discribe a complex system using 
mathematics.  Fluvial geologists have very complex formulae to discribe the 
nature of water moving in a stream; when it comes down to it, building physical 
models is often a more descriptive way of demonstrating flow behavior than 
these formulae (the subtleties are often easier to detect using a physical 
model).

Rob Meyerson
Orphan Vertebrate Paleontologist

***
The most exciting phrase to hear in science, the one that heralds new 
discoveries, is not "Eureka!" (I found it!) but  "That's funny ..."
       --  Isaac Asimov