Re: Archaeopteryx and Flight

[NEIL CLARK <NCLARK@museum.gla.ac.uk>]

> I have a nagging feeling that this great evolutionary event came 
> about as 
> a result of a complex series of events, and that we may be trying to 
> simplify it too much by reducing it to any single specific event 
> (principle of parsimony notwithstanding).
> 
> Shaun Sinclair

Why?  Why should there have been any evolutionary pressure to 
develop flight at all?  Within the range of intraspecific variation, there 
may have been an extreme morph that allowed for flight.  Due to the 
lack of competition in this area, the morph was able to alienate itself 
further from the non-flighted morphs especially after the demise of the 
pterosaurs.  The fossil record provides us with a limited look at what 
was probably a wide morphological range of mutations, variants and 
your average morph.  The average morph was probably the most 
abundant, and is the most likely to be found as fossils, and probably 
never gave rise to flighted animals.  The converse may also be true, 
that all we are finding are the variants that were unsuccessful in flight 
that were forced to live in an environment near to where they are now 
found.  It is difficult to know what happened in the early stages of 
flight due to the paucity of feathered fossils.  Even arthropod workers 
looking at thousands + of representatives of the same species have 
difficulty sometimes in developing evolutionary trends as many 
intraspecific variants have been recognised as different species (this 
is slowly changing with more morphometric work).  It is always 
important to place the theories of the development of flight into 
context (a bit like teaching your gran to suck eggs in most cases:)) as 
we are dealing with a very small number of specimens, from a very 
small number of localities.  At this stage every new find will 
probably yield a new understanding (Waffle, waffle, waffle 
etc...etc...etc :)).

I've said enough now.  Please be careful over the Holidays and don't 
try jumping out of trees.  It is unlikely that your particular morph is 
developed enough for flight.

Best wishes for the new year...


Neil Clark
Curator of Palaeontology
Hunterian Museum
University of Glasgow
email: NCLARK@museum.gla.ac.uk

Mountains are found in erogenous zones.
(Geological Howlers - ed. WDI Rolfe)