Evolution goes viral! (And how real science works)

I have just one good thing to say about Behe’s book: the rebuttals have introduced me to some splendid science, such as this: a four-mutation sequence with enhanced function at each step, refuting all three of Behe’s arguments; and reproducible!

Telliamed Revisited

This is the fourth in a series of posts about a new book by Michael Behe, Darwin Devolves. Behe is a leading proponent of intelligent-design creationism (IDC), which asserts that known processes cannot adequately account for evolution and, therefore, some intelligent agent must be involved in the process. Behe is a professor of biochemistry, which gives him knowledge and credentials that most IDC advocates do not have. However, my posts explain why I think his logic is unsound and his evidence weak and biased.

In brief, Behe argues that random mutation and natural selection are almost entirely degradative forces that break or blunt the various functions encoded by genes, producing short-term advantages that are so pervasive that they prevent constructive adaptations, which he claims are very unlikely to emerge in the way that evolutionary biologists have proposed. Unlike young-Earth creationists, Behe accepts the descent of living species from common…

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About Paul Braterman

Science writer, former chemistry professor; committee member British Centre for Science Education; board member and science adviser Scottish Secular Society; former member editorial board, Origins of Life, and associate, NASA Astrobiology Insitute; first popsci book, From Stars to Stalagmites 2012

Posted on March 8, 2019, in Evolution, Science and tagged , , , . Bookmark the permalink. 4 Comments.

  1. John Wiltshire

    Michelangelo started with a large block of marble and, by REMOVING the material he crafted his famous statue of David. Single Point Mutations to DNA get a lot of attention, perhaps because the Creationists don’t want to encourage dialogue about other forms of genetic mutation.

    Gene duplication has been a major evolutionary driving force and it is easy to see how it could happen, and once it happens, we have the genetic equivalent of Michelangelo’s block of marble that can be chipped away at by SPM’s without loss of the original function to evolve whole new capabilities.

    HOX gene duplications were particularly significant:

    https://www.sciencedirect.com/science/article/pii/S0012160613001334

    Liked by 1 person

    • HOX of course is only relevant for more complicated organisms than those discussed here, but I like your sculptural analogy. For religious reasons, Behe pretends that all evolution is like a designer working on marble, when in fact it’s more like a kid playing with plasticine, adding and subtracting lumps, with as you say the addition of working material by gene duplication being extremely important, especially in higher organisms. The example Lenski is discussing here shows a phage undergoing four separate mutations, each one enhancing a previously existing function, and with a novel function emerging from the total set. This violates Behe’s imagined constraints on novelty, and also on many-mutation processes. And Lenski does it reproducibly!

      Liked by 1 person

  2. christine janis

    This is really how I’ve kept up with the biology outside of my specialty, by reading responses to creationists. Great stuff!

    Like

  3. John Wiltshire

    It can of course be dangerous to push analogies too far. However, your plasticine idea led me to picture Michelangelo as a child. Who, because there’s not much snow in Italy, progressed from making mud pies to making Mudmen. In time, the mud slowly dried out and re-crystallised into marble, and, as Michelangelo grew up, his increasingly discerning eye presented more demanding fitness challenges that potential modifications had to aspire to before they could be incorporated by the REMOVAL of material.

    Pushing on a bit further, perhaps Michelangelo had a sister who was as good at crafting heads as he was at crafting bodies. The joyous moment when the head was installed in its proper place on the body is perhaps analogous to the formation of the first eukaryotic cell by the MERGER of two distinct prokaryotic cells.

    The excellent work on phage evolution is a dramatic demonstration that the Creationist’s “Evolution has never been SEEN to happen” is simply not true. However:

    “Unlike young-Earth creationists, Behe accepts the descent of living species from common…”

    He promotes the Micro v Macro evolution argument and would no doubt assert “The modified phage is still a phage.”

    In response we can ask “Is the eukaryote cell still a prokaryote?”, “Is a vertebrate with its quadrupled HOX genes still an invertebrate?”

    Creationists should be remined of:

    Orgel’s Second Rule: “Evolution is cleverer than you are.”

    Liked by 2 people

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