Here’s a definition of exaptation:
a trait, feature, or structure of an organism or taxonomic group that takes on a function when none previously existed or that differs from its original function which had been derived by evolution. – Merriam-Webster
In other words, a feature that once served one purpose now serves another.
How is that not intelligent?
The earliest ancestors of turtles likely evolved shells not for protection, but to serve as platforms for burrowing underground. Legs seem neatly adapted for locomotion on land, but leg-like limbs were present in a 375-million-year-old fish known as Tiktaalik, and were likely used for propping the fish up in shallow water. There are exaptations in genes, too. A gene called Distal-less controls coloration on the wings of butterflies, but since it’s found in many other animals, it likely had different jobs in the ancient past. Human symbolic thinking may even be an exaptation, argues paleoanthropologist Ian Tattersall, since the brain regions that control it evolved long before signs of language or art first appeared in the archaeological record.
Furthermore, exaptation clearly demonstrates that evolution is not in the least bit intelligent. Rather, evolution is a messy process of mistakes, recycling, and repurposing, a collection of chance capable of creating life mesmerizingly strange and breathtakingly beautiful.Ross Pomeroy, “Exaptation Shows That Evolution Is Not Intelligent” at RealClear Science
This article is more just-so nonsense. It opens with the example of the feather being an exaptation, but as Mike Denton points out in his Evolution: Still a Theory in Crisis, recent analysis reveals the feather as “having no homolog in any antecedent structures” (see pp. 170-73).
But let’s play along with their fairy tale. Notice how, even if we assume feather-like structures on dinosaurs were formed initially as insulators, that Pomeroy shifts from feathers as insulators to flight as an example of the “messiness” of evolution. But how does the repurposing of a structure demonstrate messiness? This is merely a subjective conclusion of the author. Might it not just as easily demonstrate intelligent guidance? In fact, isn’t that a more reasonable conclusion to draw?
If I take a tarp and drape it over tree limbs to form a tent, is that “messy” trial and error? Such a question hardly deserves an answer since the intelligent design is obvious. In writing about spandrels (just a variation on the theme of exaptations), Sidney Brenner objected to the concept because, in his words, “There is too easy a transition from the analogy of [spandrels or expatations] to the Great Designer and his intentions.” See Current Biology (24 Sept. 1998): R669. Whatever we may think of Brenner’s objection it is at least a coherent inference drawn from the evidence.
It would be interesting to know what Pomeroy would consider “intelligent.”
See also: New biography of the original ID guy, Alfred Russel Wallace (by Michael Flannery)
Michael Flannery on Ken Miller’s podcast at Scientific American: “More nonsense”