RE: paleonet Origin of birds

["resperante" <resperante@xxxxxxxxxxxx>]

So, how can the study of MODERN organisms provide clues about the evolution
of flight millions of years ago? I wonder if the amount of inference and
assumptions is higher than the actual evidence bones provide to answer the
question. 

A few months ago I read Larry Martin's statement cited in Pat Shipman's book
Taking Wing (p. 102), which is very relevant to this issue:"The very first
thing you do, when you look at a map or anything unknown, is that you
recognize all the familiar landmarks that you've already seen. Now if you've
never worked on birds, and you've worked on dinosaurs, when you look at
Archaeopteryx, you're going to see the dinosaur. And if your primary work is
on birds, then when you look at Archaeopteryx, you're apt to see the bird."

If that is the case with Archaeopteryx, I wonder if the same is applied to
inferring evolutionary trends through comparative studies of modern or other
ancient birds. The issue is that evolutionary inferences (interpretations)
are as subjective as the evidence from the specimens is.

Raul Esperante

-----Original Message-----
From: paleonet-owner@nhm.ac.uk [mailto:paleonet-owner@nhm.ac.uk] On Behalf
Of Dinogeorge@aol.com
Sent: Tuesday, April 12, 2005 11:16 PM
To: paleonet@nhm.ac.uk
Cc: Dinogeorge@aol.com
Subject: Re: paleonet Origin of birds


In a message dated 4/12/2005 9:19:46 P.M. Pacific Standard Time,  
jpenkethman@ispwest.com writes:

>>If anyone has time for this: How can you tell whether it was  the 
>>ancestor
of
the flightless bird that could fly, or it will be the  descendants that
would become capable of flight. In other words, how can you  tell the
direction of evolution from a fossil?<<
 
You can't. You can't even tell from a cladogram. You have to reason from  
physical principles, and from known evolutionary trends in modern
organisms.