Wednesday, August 05, 2009

Lateral Gene Transfer and the Return of Lamarckian Evolution

Mark Buchanan believes that physics has entered a new era where it has gone beyond the fundamental forces into the realm of "collective phenomena". He claims that biology is about to do the same as he explains in an article that was just published in Nature Physics: "Collectivist Revolution in Evolution."
It now seems clear that biology may also have a second act linked to the widespread importance of collective phenomena. The explosion of genetic and genomic data, of course, has ushered in the era of systems biology, as biologists have come to recognize the need to gain a more holistic understanding of the functioning of organisms. But this may not be the most radical transformation in store for biological science. A coming revolution in biology, some suggest, may go so far as to unseat Darwinian evolution (ran in its modern form) from its position as the key explanatory process in biology, and may just bring back some form of Lamarckian evolution—that old idea of the inheritance of acquired characteristics.
No, it's not epigenetics, it's lateral gene transfer (LGT) that's going to unseat Darwinian evolution and bring back Lamarck.

Much of what he writes about LGT is correct. It does, indeed, make interpretation of molecular evolution more difficult, especially at the root. But some of his ideas do not represent the consensus view in biology: for example, the role of lateral gene transfer in the evolution of the genetic code.
The conjecture is that horizontal gene transfer was indeed required for the present genetic code to take the form it has, and that the emergence of life most likely went through a series of stages, with the early stage more Lamarckian in character, and only the latter stages becoming more Darwinian.

Exploring that point in greater detail will be a task for a new kind of biology, one that breaks with many of the presuppositions of traditional evolutionary thinking, and explores the potential for rich and surprising dynamics in a collective setting. It will almost surely benefit from the ideas and experience of physics, which has already experienced its own collectivist revolution.
This kind of hyperbole is not helpful. Shame on Nature Physics for publishing it.1

1. I wonder if Nature Genetics publishes opinion pieces by evolutionary biologists on the overthrow of quantum mechanics?


  1. LGT is a form of Lamarckian evolution? I don't think so!

    Is it "Lamarckian" when a bacterium takes up a conjugative R-plasmid from some other bacterium? Sure, it's an acquired characteristic that will be transmitted to the recipient's progeny, but it's grossly misleading to call that Lamarckian. By that standard, even spontaneous germ-line mutations are Lamarckian. Hey, I guess Lamarck was right all along!

    In any case it's pretty ignorant to claim that LGT could unseat Darwinian evolution as "the" key explanatory process. I don't doubt that LGT plays a significant role, but even in microbes where LGT is widespread, vertical inheritence plays an enormously greater role than LGT.

    (On top of all that, 'Darwinian' evolution has arguably been unseated already as 'the' key process, in light of what we know now about genetic drift.)

  2. What the @%*& just happened?

  3. Oh my! Lateral gene transfer will destroy Darwinism. How exciting. What a crock. Lateral gene transfer is just another source of variation.

  4. I think there is a general tendency for physics journals to publish biology related points of view from physicists.
    Easier to sound interesting to the referees maybe.
    Such a case with extensions to evodevo, reviewed here by PZ.

  5. Does Nature Physics have peer review? How could they let statements like that get published without adequate support?

  6. Oh, brother. How long before this becomes one of Casey Luskin's talking points.....

  7. I do wish physicists would get their own field in order before deigning to iinstruct us on what is coming down the pipe in biology...

  8. An honest question, as I'm not read up on the latest.

    How is the LGT problem such a huge problem? Isn't this just an new complication for the standard gene tree versus species tree representation of an organism's evolution?

    Yes, we may have lost our method for defining the LUCA, but how does this cause so much problem, that we are debating "trees as a metaphor for evolution"?