Mutation and evolution

Category: Curious Disconnect

  • The buffet and the sushi conveyor

    The return of mutationism to mainstream evolutionary biology is evident in the way mainstream articles now describe the role of mutation in evolution, in our reliance on mathematical models that evoke a mutationist view, and in evo-devo research programs that focus on identifying causative major-effect mutations. This shift has happened in a kind of sub-conscious…

  • Why the “four fundamental forces” view is mistaken

    Over at Sandwalk, Larry Moran posted some interesting bits rrom his molecular evolution class exam, including a passage from Mike Lynch arguing for his claim that “nothing in evolution makes sense except in the light of population genetics”.  In this passage, which I’ll quote below, Lynch says that evolution is governed by 4…

  • The range of rates for different genetic types of mutations

    To understand the potential role of mutation in evolution, it is important to understand the enormous range of rates for different types of mutations. If one ignores this, and thinks of “the mutation rate” as a single number, or if one divides mutation into point mutations with a characteristic rate, and other mutations…

  • The shift to mutationism is documented in our language

    Last year Sahotra Sarkar published a paper that got me thinking.  His piece entitled “The Genomic Challenge to Adaptationism” focused on the writings of Lynch & Koonin, arguing that molecular studies continue to present a major challenge to the received view of evolution, by suggesting that “non-adaptive processes dominate genome architecture evolution”. The idea that molecular…

  • Why size matters: Saltationism, creativity, and the reign of the DiNOs

    Debates on “gradualism” in evolutionary biology address the size distribution of evolutionary changes.  The classical Darwinian position, better described as “infinitesimalism”, holds that evolutionary change is smooth in the sense of being composed of an abundance of infinitesimals (not one infinitesimal at a time, but a blending flow of infinitesimals).  …

  • Revolt of the clay: updated evidence

    In a previous post called “The revolt of the clay“, I described four different ways to think about the role of variation as a process with a predictably non-random impact on the outcome of evolution.  The main point was to draw attention to my favorite idea, about biases in the introduction of variation as…

  • The revolt of the clay: an initial progress report

    A “chance” encounter Earlier this month I was contacted by a reporter writing a piece on the role of chance in evolution.   I responded that I didn’t work on that topic, but if he was interested in predictable non-randomness due to biases in variation, then I would be happy to…

  • Conceptual frameworks and the problem of variation

    Conceptual frameworks guide our thinking Our efforts to understand the world depend on conceptual frameworks and are guided by metaphors.  We have lots of them.  I suspect that most are applied without awareness.  If I am approaching a messy problem for the first time, I might begin with the idea that there are various “factors”…

  • Randomness in Evolution (Bonner)

    John Tyler Bonner’s Randomness in Evolution (2013; Princeton University Press) is a small and lightweight book— 123 pages, plus a bibliography with a mere 43 references.  So, I won’t feel too bad for giving it a rather small and lightweight review, based on a superficial reading.   Last year, I was tasked…

  • The surprising case of origin-fixation models

    In a recent QRB paper with David McCandlish, we review the form, origins, uses, and implications of models (e.g., the familiar K = 4Nus) that represent evolutionary change as a 2-step process of (1) the introduction of a new allele by mutation, followed by (2) its fixation or loss. What could…