RE: Digit Loss

["Tracy Ford" <dino.hunter@home.com>]

-----Original Message-----
From: Oscar Quill [mailto:stonebugdotnet@yahoo.com]
Sent: Friday, June 08, 2001 1:33 PM
To: dino.hunter@home.com; Dinosaur Mailing List
Subject: RE: Digit Loss


--- Tracy Ford <dino.hunter@home.com> wrote:

> But they don't. The fingers have good claws, strong
> fore-limbs.
> Tyrannosaurus rex has larger arms in relation to
> it's body than many earlier
> tyrannosaurids.


Interesting.  Which tyrannosaurids have shorter
forelimb proportions than T. rex?<<

I've done some research on this. Tarbosaurus, Albertosaurus, Gorgosaurus,
Daspletosaurus all have humerus/femur ration as 1/4. In Tyrannosaurus it is
1/3, thus a larger arm in relation to body.


...
> If life is just a act of mutations (which is the
> drift I get from this
> thread) then why is there so many body morphs that
> keep cropping up during
> evolution? I'm noticing more and more of this.
> Estemmenosuchids and wart
> hogs, Long skulled labyrinthodonts, phytosaurs and
> gavials, and numerous
> others. How can all this be just an act of mutation?
> Question open to group
> discussion.


Perhaps these body shapes are strange attractors by
way of these animals' inhabiting similar environments,
living similar lifestyles, etc.  Obviously there's
still differences, but perhaps as a general rule,
certain physical attributes can be expected to evolve
independently again and again simply by virtue of
being the best means of adaptation to a particular way
of living, feeding, etc.<<

I have not problem with this. But how would radom mutation keep repeating
body morphs if environment didn't have a role in it? From the thread I
gather everything is radom chance, or am I misreading what others have said?



Tracy L. Ford
P. O. Box 1171
Poway Ca  92074