In a review of Michael Behe’s Darwin Devolves, Terry Scambray talks about examples of devolution, often promoted as evolution:
According to Darwin, the twin dynamics of mutation and natural selection account for such systems. These dynamics are demonstrated in polar bears, which separated from their brown-bear cousins hundreds of thousands of years ago — a separation triggered at the genetic level by two damaging mutations. One was in a gene called APOB, which is involved in metabolizing fat and helps polar bears ingest copious amounts of seal blubber. The second gene, LYST, codes for skin pigmentation and probably made the fur of polar bears white. Computer analysis of these genes shows that each mutation damaged their original functions. This squashing of genetic information by mutations initially helped one or several bears, perhaps, to survive in the new, frigid environment to which they had relocated for whatever reasons. Then, as bears with intact genetic information began to die off or remain in warmer climates, the lucky losers of genetic information began to grow in numbers, then predominate, until finally bears with these two traits became ubiquitous in their Arctic home. So, the polar bear, Behe writes, “adjusted to its harsh environment mainly by degrading its genes that its ancestors already possessed. Despite its impressive abilities, rather than evolving, it has adapted predominately by devolving.” What this “portends for our conception of evolution,” Behe explains, is “the principal topic” of Darwin Devolves…
Behe offers another example of a mutation that breaks off one-third of the protein in a gene that influences the nervous system of horses. This impaired gene causes the horse that carries it to maintain a smooth trot, a trait that has been bred by horse breeders. …
So, if most mutations warp or destroy what’s already in the DNA of an organism, and circumstances permit the organism to live or die, where’s the step-by-step pathway upward to the new and improved versions, the evolutionary progress that Darwin’s science supposedly demonstrated? Darwinian change is supposed to be vertical, a bottom-up movement. Instead, what Behe sees is a top-down movement: Organisms arrive with their genetic complexity intact, undergo mutations, and, as a consequence, sometimes move horizontally, back and forth within a species. Behe recounts Darwinists’ various self-organizing theories, but none accounts for the type of change in question, let alone for the sophisticated cellular machinery itself.
Terry Scambray, “Review of Darwin Devolves” at New Oxford Review (July-August 2020) (paywall)