Evolution: a different view (Introduction)

by dhw, Saturday, May 02, 2015, 08:39 (3493 days ago) @ David Turell

Please note: I am putting the exaptation arguments together on this thread, which seems more appropriate than "Evolution v Creationism".-dhw: ...exaptations would also be inventive adjustments to existing organs.
DAVID: Exaptation's appear thousands to hundred of thousand years before any use is found for them. That is a key issue in the idea of pre-planning. 
And: You totally miss the point about exaptation's. They appear well before any use of them is found and they are not necessary at the time of appearance. That is the definition of them.-I can't find any definition that supports this view. On one website I found the following definitions:
1. a process in which a feature acquires a function that was not acquired through natural selection. 
2. a feature having a function for which it was not originally adapted or selected. 
3. a morphological or physiological feature that predisposes an organism to adapt to a different environment or lifestyle. 
4. predisposition toward adaptation.-None of these definitions suggest features that have hung around for thousands of years doing nothing. If anything, they seem to suggest innovative use of existing features.
 
Another site offers the following illuminating comment and example: 
"It is a relatively new term, proposed by Stephen Jay Gould and Elisabeth Vrba in 1982 to make the point that a trait's current use does not necessarily explain its historical origin. They proposed exaptation as a counterpart to the concept of adaptation.
For example, the earliest feathers belonged to dinosaurs not capable of flight. So, they must have first evolved for something else. Researchers have speculated early feathers may have been used for attracting mates or keeping warm. But later on, feathers became essential for modern birds' flight."
 
This seems to be a classic example. Feathers originally served a different purpose. They didn't magically appear and hang around for yonks doing nothing until some cleverclogs decided to use them in order to fly. Another website gives the example of fins becoming limbs - not a useless feature suddenly becoming useful, but an existing feature taking on a new function. You regard the lowering of the larynx as another, and refer to it as “the descent of the larynx, long before language”. And: “Lucy had no idea she could one day learn to speak.” How do you imagine these early hominids communicated? Do you not think they made sounds? And do you not think their lowered larynx would have helped them to make different sounds using their own particular “language”? Or do you mean Lucy had no idea she could one day learn to speak English?