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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 ›

Recently a paper appeared by Ratcliff et al. (2012) entitled “Experimental evolution of mulitcellularity” and received a fair amount of press attention, including a story in the New York Times. (http://tinyurl.com/6va4fpp ) The authors discuss their results in terms of the origin of multicellularity on earth. The senior author of the paper is Michael Travisano of the University of Minnesota, who was a student of Richard Lenski’s in the 1990s. The paper, published in PNAS, was edited by Lenski. The gist is as follows. The authors repeated three steps multiple times: 1) they grew single-celled yeast in a flask; 2) briefly centrifuged it; and 3) took a small amount from the bottom of the flask to seed a new culture. This 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 ›

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 clear limits 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 ›

Several papers on the topic of “evolvability” have been published relatively recently by the laboratory of Richard Lenski. (1, 2) Most readers of this site will quickly recognize Lenski as the Michigan State microbiologist who has been growing cultures of E. coli for over twenty years in order to see how they would evolve, patiently transferring a portion of each culture to new media every day, until the aggregate experiment has now passed 50,000 generations. I’m a huge fan of Lenski et al’s work because, rather than telling Just-So stories, they have been doing the hard laboratory work that shows us what Darwinian evolution can and likely cannot do. The term “evolvability” has been used widely and rather loosely in Read More ›

In my last post I reported that University of Chicago evolutionary biologist Jerry Coyne, who had critiqued (http://tinyurl.com/2fjenlt) my recent Quarterly Review of Biology article (http://tinyurl.com/25c422s) concerning laboratory evolution studies of the last four decades and what they show us about evolution, had asked several other prominent scientists for comments (http://tinyurl.com/2cyetm7). I replied (http://tinyurl.com/4lq8sre) to those of experimental evolutionary biologist John Bull. In a subsequent post Coyne discussed (http://tinyurl.com/4tqoq7c) a recent paper (http://tinyurl.com/4shw456) by the group of fellow University of Chicago biologist Manyuan Long on gene duplication in fruitflies. After a bit of delay due to the holidays, I will comment on that here. Try as one might to keep Darwinists focused on the data, some can’t help reverting to Read More ›

At his blog (http://tinyurl.com/2cyetm7) University of Chicago professor of evolutionary biology Jerry Coyne has commented on my reply (http://tinyurl.com/383zqm7) to his analysis ((http://tinyurl.com/2fjenlt) of my new review (http://tinyurl.com/25c422s) in the Quarterly Review of Biology. This time he has involved two other prominent scientists in the conversation. I’ll discuss the comments of one of them in this post and the other in a second post. The first one is University of Texas professor of molecular biology James J. Bull, who works on the laboratory evolution of bacterial viruses (phages). I reviewed a number of Bull’s fascinating papers in the recent QRB publication. Coyne solicited Prof. Bull’s comments and put them up on his blog (http://tinyurl.com/2cyetm7). Bull says several nice things about Read More ›

At his blog, Why Evolution is True (http://tinyurl.com/2fjenlt), Jerry Coyne, professor of evolutionary biology at the University of Chicago, has been analyzing my recent paper, “Experimental Evolution, Loss-of-Function Mutations, and ‘The First Rule of Adaptive Evolution’” (http://www.lehigh.edu/~inbios/pdf/Behe/QRB_paper.pdf), which appears in the latest issue of the Quarterly Review of Biology. Although I usually don’t respond to blog posts I will this time, both because Coyne is an eminent scientist and because he does say at least one nice thing about the paper. First, the nice thing. About half-way through his comments Professor Coyne writes: My overall conclusion: Behe has provided a useful survey of mutations that cause adaptation in short-term lab experiments on microbes (note that at least one of these Read More ›

In its most recent issue The Quarterly Review of Biology has published a review by myself of laboratory evolution experiments of microbes going back four decades. The paper (entitled “Experimental Evolution, Loss-of-Function Mutations, and ‘The First Rule of Adaptive Evolution’”) is available as a free pdf on my Lehigh University website (http://www.lehigh.edu/~inbios/pdf/Behe/QRB_paper.pdf). The chief question asked in the paper is the following: does evolution more often proceed by endowing an organism with a new function, by taking away an existing function, or by tweaking (modifying) a pre-existing function? Darwin himself realized that evolution did not always have to proceed by gain-of-function events. For example, in some of his writings he described male barnacles that had undergone gross simplification. For most Read More ›