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RE: very general remark (and other stuff)



Jerzy Dyczkowski wrote:

>Examples of recent stringy or false opinions were: poorly flying birds
>cannot colonise through the oceans, terrestial birds with long legs are
>adapted for running, top carnivores can be primarily scavengers,
>predation on predators is rare.

The above statements are all true - to a degree.  But, as they are all
sweeping statements, it's difficult to argue for or against them.  It's like
asking, "how long is a piece of string?"

For example, *certain* terrestial birds with long legs are
indeed adapted for running.  Emus and rheas, for example.  Others
terrestrial birds are not; the secretary bird and certain ground-feeding
gallinaceous birds are good examples.  They would rather fly then run in
order to cover long distances (such as when escaping predators).


>Del Hoyo, Handbook of the birds of the world
>(expensive, but very detailed available in public libraries)

This is a superb series (the final volumes are still in production) and I
wouldn't recommend buying it unless you're (a) Bill Gates or (b) willing to
take out a second mortgage.  The only criticism I have is that I wish
individual references were cited throughout the text.


Ken Kinman wrote:

>The biggest doesn't necessarily have to be the smartest brain, but I 
>certainly couldn't be communicating with you all if I had the brain of a 
>therapsid, much less the brain of a Devonian amphibian. 

Ahh, but you *do* have the brain of a therapsid, Ken.  

By that I mean that mammals are a subset of therapsids; the Mammalia is the
only surviving lineage of the Therapsida.

And before somebody writes back saying "But he MEANT the extinct therapsids,
NOT mammals!!!!", I'll point out that the demarcation between the two is
totally arbitrary and in a constant state of flux.

Ken Kinman also wrote:

> Is the word 
> "progress" so politically incorrect that we have to ignore the obvious 
> trends.  This just seems like an overreaction to past mistakes, and the 
> pendulum gets swung too far the other way. 

To which David Marjanovic replied:

>Who cares about political correctness. Progress as a main component of 
>evolution is just a falsified hypothesis. 

I'm with David on this one.  "Progress" is a purely anthropocentric concept,
imposed by us on evolutionary pathways that display traits that we (as
big-brained, bipedal primates) can identify with.  If tapeworms could write
textbooks, they would consider _Homo sapiens_ as evolutionary revenants. 


Tracy Ford wrote:

> >Maybe the tuberculate morphology is typical of ornithischian skin, and >
>the "granicones" belong to _Echinodon_ after all. << 

>Well, I just looked at figures of the Granicones in Don Gluts Dinosaur 
>Encyclopedia supplment no 2 (page 321 for those who have it) and they DO
>NOT look like the skin of the hadrosaur. 
[snip]
>Those large scutes have large 'serrated' edges, while the granicones >have
a more oval base and are pointed. It just may be the authors who, >actually
have seen the granicones and compared them to heloderma 
>(strange concept just looking at specimens for some) are right on this
>one. 

Maybe they are.  I wasn't contradicting Barrett and Clarke; merely
highlighting another specimen for potential comparison.  Just trying to
help.



Tim

------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163