RE: Yet more on dinosaur quad climbers

[Jason Brougham <jaseb@amnh.org>]

Well you have a point. This new book I'm very keen to read, Relentless 
Evolution (Thompson, J. N.; 2013), makes the case for extremely rapid 
evolution. But we can't be certain that halluces are inevitable can we? A 
gripping foot and limited flapping ability may have served just fine for 
millions of years. As you suggest we cannot, from a priori theory (armchair 
proclamations) alone decide what should have happened in evolution. Evolution 
is stochastic, based on random occurrences. 

Halluces, in fact, may have arisen just once, in the last common ancestor of 
Confuciusornis and all crown group birds, and been inherited by 
enantiornithines as well.

Now I'm getting re-interested in incipient flight from the ground. The Kagu 
(Rhynochetos) roosts in trees at night, but dwells on the ground. It is very 
hesitant to fly but, if pressed, will flap about 4 meters over streams and 
whatnot. It has large wings, and has the same mass and wingspan as Microraptor. 
It has no sternal keel.
________________________________________
From: owner-DINOSAUR@usc.edu [owner-DINOSAUR@usc.edu] on behalf of David 
Marjanovic [david.marjanovic@gmx.at]
Sent: Saturday, July 13, 2013 8:35 AM
To: dinosaur@usc.edu
Subject: Re: Yet more on dinosaur quad climbers

Collected thoughts...

-- Mike Habib's e-mails, even the latest one, arrive here without line breaks 
in their paragraphs; my interface wraps the lines at the edge of the window, 
but there are some that don't do that and instead have you scroll horizontally 
for enormous distances. The reason may be that Windows linebreaks and Mac 
linebreaks aren't the same character.

-- "What use is half a wing?" That's the classical question. Parachuting? 
Gliding? Display? Brooding?

-- The GFTR hypothesis still needs a way to get from gliding to flapping. I'm 
also not sure if a glider rather than a parachuter would really result, and why 
a perching foot or some other such adaptation wouldn't evolve pretty soon after 
selection pressure for roosting set in. The weka kept falling off.

-- Weird shit happens.
fallacy.

-- The ability to retract the head into the shell evolved twice independently 
in turtles, and not very soon. *Proganochelys* and *Meiolania*, to mention just 
two, were clearly incapable of any such retraction.

-- Brooklyn isn't mythical in the mind of the world at all. Most of the world 
only knows it's part of New York. And the only person I've seen quoting 
themself as a signature before was John A Davison.