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Topic of the Day #1



To all the other Gotta's, wanna's and interested parties

Discuss or comment, for one day only, the topics of:

The Curorial (From the ground up)
and Arboreal (down from the trees)
method of evolving flight.

Remember, that evolution takes place for a reason. For 
example, a flightless creature evoloving into a flighted 
creature will not suffer small, medium sized half formed 
wing for a few hundred generations, each step will/ must be 
beneficial to the individual, before it can become benificial 
to the species.

An example of this comes from the compognathus (relative but 
not ancestor of the Archaeopteryx) a lizard around in the 
Jurassic, found in the Solenhofen Limestone. It eloved longer 
hind legs (for running and jumping) and a long tail (for 
balance). It used it's smaller forelimbs to hunt prey. It fed 
on insects. To hunt insects more efficiently it legs evolved 
to jump, allowing it to catch more. The Archaeopteryx was 
very similay, but had evolved tail feathers for balance 
rather then a long tail, and had evolved small feathered 
wings, not usable for true flight but when used helped the 
creature attain a little more hieght in a jump, and maintain 
it a little longer, clearly an advantage when hunting flying 
insects. 

That was an example of Curorial evolution, from the ground 
up. 

In brief, the trees down method involves three steps, "Climb 
trees", "Glide down", "Flap wings - true flight"


----------------------
Matt
mss196@soton.ac.uk