Darwin Devolves (book)

Here’s an example of what Michael Behe is (actually) talking about in Darwin Devolves The evolution strategy “Break or blunt any functional coded element whose loss would yield a net fitness gain”: Eleven authors writing in PLOS Biology found that “γ-proteobacteria eject their polar flagella under nutrient depletion, retaining flagellar motor relic structures.” When there’s nothing to eat, these bacteria are willing to toss off their flagella and plug the hole in order to save energy. If you were out on a lake, would you unlatch your new Yamaha F250 4.2-liter V6 outboard motor and let it drop to the bottom? You might if the boat was taking on water and was about to sink, and you were about to Read More ›

In a review, one reviewer has decided to talk about what Michael Behe actually says in Darwin Devolves. For example, In a section called “The Blind Metaphor,” Behe notes: “The primary way by which natural selection makes evolution self-limiting is by promoting poison-pill mutations. Whatever genetic alterations that help an organism survive and reproduce better than its competitors will be fodder for natural selection—even if the alterations make a species less able to adapt in the future (200). In hindsight, that is what we should have expected. Despite the boost in plausibility it receives from its metaphorical name, over multiple rounds natural selection is clearly nothing like the opposite of chance, no more than, say, gravity is the opposite of Read More ›

In American Association for the Advancement of Science’s magazine, Science,  we read, In the grand scheme of evolution, mutations serve only to break structures and degrade functions, Behe argues. He allows that mutation and natural selection can explain species- and genus-level diversification, but only through the degradation of genes. Something else, he insists, is required for meaningful innovation. Here, Behe invokes a “purposeful design” by an “intelligent agent.” There are indeed many examples of loss-of-function mutations that are advantageous, but Behe is selective in his examples. He dedicates the better part of chapter 7 to discussing a 65,000-generation Escherichia coli experiment, emphasizing the many mutations that arose that degraded function—an expected mode of adaptation to a simple laboratory environment, by the Read More ›