<<Preadaptations can be recognized only in retrospect. They are simply
adaptations at the time, and their future utility cannot be anticipated by
the organism. The examination of the fossil record seems to indicate that
the initial appearance of a novel character is associated with a function
unrelated, or only tangentially related, to its eventual function. In this
case, these structures certainly did not have a flight function, but likely
did have some thermoregulatory purpose. Once they exist, they are then
subject to other selective forces that may co-opt them for other purposes.
>>
I understand the concept of preadaptation. But I am skeptical of your
suggestion that the "filamentary integuments" had a thermoregulatory
function, that was later co-opted for the function of flight. This is highly
speculative and sounds reasonable because it fits into the evolutionary
paradigm. Could not one just as reasonably speculate that "filamentary
integuments" are a step in a design process that extends over time that was
intended from the beginning to produce feathers for flight? This fits the
design paradigm. How does one decide which is the best explanation?
Best regards,
Bob