irreducible complexity

Recently a new paper by Richard Lenski and colleagues (Meyer et al 2012) appeared in Science with, as usual, commentary in the New York Times. (Lenski’s lab must own a red phone with a direct line to The Gray Lady.) The gist of the paper is that a certain bacteriophage (a virus that infects bacteria) called “lambda” gained the ability to bind a different protein on the surface of its host, the bacterium E. coli, than the protein it usually binds. The virus has to bind to the cell’s surface as a prelude to invading it. The protein it normally binds is called LamB. Lenski’s lab, however, used a bacterial strain that had turned off the production of LamB in 99% of E. coli cells but, Read More ›

I never thought it would happen but, in my estimation, Richard Lenski has acquired a challenger for the title of “Best Experimental Evolutionary Scientist.” Lenski, of course, is the well-known fellow who has been growing E. coli in his lab at Michigan State for 50,000 generations in order to follow its evolutionary progress. His rival is Joseph Thornton of the University of Oregon who, by inferring the sequences of ancient proteins and then constructing (he calls it “resurrecting”) their genes in his lab, is able to characterize the properties of the ancestral proteins and discern how they may have evolved into more modern versions with different properties. I have written appreciatively about both Lenski and Thornton before, whose work indicates Read More ›

An intriguing ‘hypothesis’ paper entitled “How a neutral evolutionary ratchet can build cellular complexity” (1), where the authors speculate about a possible solution to a possible problem, recently appeared in the journal IUBMB Life. It is an expanded version of a short essay called “Irremediable Complexity?” (2) published last year in Science. The authors of the manuscripts include the prominent evolutionary biologist W. Ford Doolittle. The gist of the paper is this. The authors think that over evolutionary time, neutral processes would tend to “complexify” the cell. They call that theoretical process “constructive neutral evolution” (CNE). In an amusing analogy they liken cells in this respect to human institutions: Organisms, like human institutions, will become ever more ”bureaucratic,” in the sense Read More ›

The science writer Carl Zimmer posted an invited replyhttp://tinyurl.com/yhpm3t7 on his blog from Joseph Thornton of the University of Oregon to my recent comments about Thornton’s work. This is the last of four posts addressing it. References appear at the bottom of this post. At the end of his post Thornton waxes wroth. Behe’s argument has no scientific merit.  It is based on a misunderstanding of the fundamental processes of molecular evolution and a failure to appreciate the nature of probability itself.  There is no scientific controversy about whether natural processes can drive the evolution of complex proteins.  The work of my research group should not be misintepreted by those who would like to pretend that there is. Well, now. I’ll Read More ›

The science writer Carl Zimmer posted an invited replyhttp://tinyurl.com/yhpm3t7 on his blog from Joseph Thornton of the University of Oregon to my recent comments about Thornton’s work. This is the second of several posts addressing it. References will appear in the last post. Now to Professor Thornton’s reply. He writes at length but makes just two substantive points: 1) that neutral mutations occur and can serendipitously help a protein evolve some function (“[Behe] ignores the key role of genetic drift in evolution”); and 2) that just because a protein may not be able to evolve a particular function one way does not mean that it, or some other kind of protein, can’t evolve the function another way (“nothing in our results Read More ›

Dear Readers, Recently a paper appeared online in the journal Proceedings of the National Academy of Sciences, entitled “The reducible complexity of a mitochondrial molecular machine” (http://tinyurl.com/mhoh7w). As you might expect, I was very interested in reading what the authors had to say. Unfortunately, as is all too common on this topic, the claims made in the paper far surpassed the data, and distinctions between such basic ideas as “reducible” versus “irreducible” and “Darwinian” versus “non-Darwinian” were pretty much ignored. Since PNASpublishes letters to the editor on its website, I wrote in. Alas, it seems that polite comments by a person whose work is the clear target of the paper are not as welcome as one might suppose from reading the journal’s Read More ›

Dear readers, I’ve just been through the weirdest book-related experience I’ve had since a Canadian university professor with a loaded rat trap chased me around after a talk I gave a dozen years ago, threatening to spring it on me. Last week I got the following email bearing the title “Invitation to Appear on Bloggingheads TV” from a senior editor at that site: ************* Hi, Michael– I’d like to invite you to appear on Bloggingheads.tv, a web site that hosts video dialogues between journalists, bloggers, and scholars. We have a partnership with the New York Times by which they feature excerpts from some of our shows on their site. Past guests include prominent thinkers such as Paul Krugman, Paul Ehrlich, Read More ›

Dear Readers, An interesting paper has just appeared in the Proceedings of the National Academy of Sciences, “Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli.” (1) It is the “inaugural article” of Richard Lenski, who was recently elected to the National Academy. Lenski, of course, is well known for conducting the longest, most detailed “lab evolution” experiment in history, growing the bacterium E. coli continuously for about twenty years in his Michigan State lab. For the fast-growing bug, that’s over 40,000 generations! I discuss Lenski’s fascinating work in Chapter 7 of The Edge of Evolution, pointing out that all of the beneficial mutations identified from the studies so far seem to have been degradative ones, where functioning genes are knocked out or Read More ›

This is the fourth of five posts in which I reply to Dr. Ian Musgrave’s “Open Letter to Dr. Michael Behe” on the Panda’s Thumb blog. And now let’s talk about Dr. Musgrave’s “core argument,” that subsequent to the virus leaping to humans from chimps Vpu developed the ability to act as a viroporin, allowing the leakage of cations which helps release the virus from the cell membrane. Yes, I’m perfectly willing to concede that this does appear to be the development of a new viral protein-viral protein binding site, one which I overlooked when writing about HIV. So the square point in Figure 7.4 representing HIV should be placed on the Y axis at a value of one, instead Read More ›

The current edition of The New Criterion carries a lengthy reviewof The Edge of Evolution (subscription required) by the biochemist Paul Gross. Unfortunately, although he is commendably civil and kindly praises my writing and speaking abilities, Gross offers little of actual substance other than to declare the book’s arguments wrong. He quotes Ken Miller saying that the malaria calculations are wrong, and alludes to Sean Carroll’s declaration that, why, there is a vast number of (unspecified) papers showing how protein binding sites can evolve. For rejoinders to those claims, I refer readers to my comments on this blog concerning Carroll’s and Miller’s reviews.