evolution

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 ›

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 ›

University of California evolutionary biologist John Avise has penned a book, Inside the Human Genome: A Case for Non-Intelligent Design, and gotten it published by a top academic publishing house, Oxford University Press. Avise, a member of the National Academy of Sciences, has for decades been a leading researcher in evolutionary and ecological genetics. He has written hundreds of research articles and over a dozen books. Clearly he has an impressive scientific mind. Which makes it all the more astonishing that his new book shows all the intellectual savvy of a typical late-night college dormroom bull session. As his subtitle announces, Avise is anxious to show that, despite the claims of certain renegade biochemists, the molecular features of the human genome 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 ›

The January 2009 issue of Trends in Microbiology contains an article entitled “Bacterial flagellar diversity and evolution: seek simplicity and distrust it?”  Unfortunately, like many people, the authors have a mistaken view of irreducible complexity, as well as a very shallow idea of what a Darwinian “precursor” to an irreducibly complex system might be. I wrote a letter to the editor of the journal to point out these difficulties. Alas, they said they had no room to publish it. Below is the letter that I sent. To the editor: In their recent article “Bacterial flagellar diversity and evolution: seek simplicity and distrust it?” Snyder et al. (2009) [1] attribute to me a view of irreducible complexity concerning the flagellum that I do Read More ›

Dear Readers, When The Edge of Evolution  The Edge of Evolution: The Search for the Limits of Darwinism  was first published, some Darwinist reviewers sneered that the problem it focused on — the need for multiple mutations to form some protein features (such as binding sites), where intermediate mutations were deleterious — was a chimera. There were no such things, they essentially said. University of Wisconsin geneticist Sean Carroll, reviewing the book for Science, stressed examples where intermediate mutations were beneficial (I never said there weren’t such cases, and discussed several in the book). In the same vein, University of Chicago evolutionary biologist Jerry Coyne assured readers of The New Republic that “[i]n fact, interactions between proteins, like any complex interaction, were certainly built up step Read More ›