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RE: A few very short questions



Most bright kids understand that evolution is like a branching bush.  Linnean 
systematics groups the leaves & twigs that are close together and gives them 
names.  That was very useful when we were simply trying to get a handle on what 
was on the bush.  Often, but not always, those structures grew from the same 
stems.

Now that we have at least an idea of what the bush looks like, we want to know 
how it got that way.  How did it grow?   Phylogenetic systematics simply tries 
to unravel the branches that have grown together.  It gives the stems and 
branch points names, regardless of what direction they lead because those are 
the relations we're now trying to understand.  It looks to process more than 
outcome, to take the analogy up one level of abstraction.

Maybe the next question will be what made it grow that way.  Hopefully, by 
then, I will have thought of some way to stretch this tired old analogy one 
more step.

  --Toby White

Vertebrate Notes @
http://www.dinodata.net
http:/home.houston.rr.com/vnotes


On Wednesday, December 08, 1999 3:21 PM, Thomas R. Holtz, Jr. 
[SMTP:tholtz@geol.umd.edu] wrote:
> Well, yes, it is almost a paradigm shift.  (You can arguably drop the
> "almost"!).
>
> How are we going to explain it?  By explaining it.  By education.