Re: Ruben Strikes Back

[Dinogeorge@aol.com]

In a message dated 9/24/99 1:37:59 PM EST, eamalitz@hotmail.com writes:

<< An interesting hypothesis- has it ever been published before? It is 
 obviously not favored by most paleontologists. >>

Well, I published a popular-science version of the present version of BCF 
("birds came first") in the June 1994 OMNI--rather in the "lunatic fringe" 
but published just the same. Also noted it in Mesozoic Meanderings #2 first 
and second printings, 1991 and 1992. But I'm still working on the fullest 
version, for the third edition of MM.

One problem with the ground-up hypothesis--aside from the vast physics 
difficulties--is that the theropod lineages leading up to flying birds each 
repeatedly lost flight adaptations and re-evolved the same kinds of 
adaptations for cursoriality and terrestriality convergently (e.g., small 
forelimbs, vestigial sternum, reduced hallux), and these convergences are 
misleading the cladistic analyses. At very least, this possibility has not 
been fully addressed in any cladistic analysis I know of.

As I've mentioned before, the ground-up hypothesis requires us to accept a 
miracle, namely, that an array of features each of which evolved 
independently as an adaptation for cursoriality, terrestriality, or predation 
suddenly gave us an animal fully adapted for flying. This is the part that 
the ornithologists simply don't buy, and why they will not accept dinosaurs 
as bird ancestors despite overwhelming cladistic evidence that this is the 
case. All that needs to be done is to decouple the ground-up hypothesis from 
the cladistic analyses--the cladistics does >not< show that flight evolved 
ground-up, because it says nothing about the lifestyle of the common 
ancestors at the nodes along the lineage leading toward birds. These common 
ancestors could well have been much more birdlike and much less dinosaurlike 
than we have imagined; the cladistic analyses would remain the same.