Gene Expression

i-b26d30171cc3d890e253453d2e3e4488-GOUSTR.jpgChapters read:1, 2, 3, 4, 5, 6 and 7.

Chapter 6 of The Structure of Evolutionary Theory was short. Yes, you read that right, this was a short chapter! It was only 38 pages, but it was also one of the most readable and fast paced. Additionally, Stephen Jay Gould told me things I didn’t know beforehand. Partly this has to be a function of the fact that because he focused on geology I was just ignorant, though his revisionism of 19th century Catastrophism and Uniformitarianism seemed well done to me. But, as I said, this is the chapter where my own knowledge has been the thinnest so far, so take that for what it’s worth. Gould makes the claim here that Charles Darwin was wedded to a very narrow and specific view of phyletic gradualism which was congenial with an extremely old earth not subject to catastrophic events. The reason for this, according to Gould, is that in that way Darwin could emphasize intraspecific competition and biotic parameters as the predominant driver of evolution through selection. Environmental factors were exogenous, and Darwin takes a Malthusian view which contends that by and large population pressure was more important than shifts in climate, soil, etc. And through intraspecific competition Darwin rescues the idea that species over time become perfected toward their adaptive peaks; that is, progress exists even in evolution and there is an element of directionality. In contrast, rapid climatic or geological changes might result in mass extinctions and other rapid evolutionary events which would go against the grain of phyletic gradualism through micoevolutionary process.

And so with that Darwin aligned himself with Charles Lyell’s Uniformitarianism and against Georges Cuvier’s Catastrophism. The standard narrative is that Cuvier was a Creationist, that Catastrophists were attempting to save the Biblical narrative despite the data. Gould contends this is a myth; rather, Cuvier and the Catastrophists were the empiricists while Lyell and his fellow travelers were ones who were more likely to extrapolate from data and assume from a priori axioms. A similar sort of revisionism also affected perception of the controversy about the age of the earth during the late 19th century, when Lord Kelvin deduced from the temperature of the crust that the world could be no more than 100 million years old, and perhaps as young as 10 million years. Today we are told that Kelvin was arrogant, and that the natural historians, geologists and biologists, stood their ground and were vindicated when radioactivity showed that the world could potentially be much older. Gould claims that the reality is that most geologists were satisfied with 100 million years, and biologists more sympathetic to saltation such as Thomas Huxley did not object much to Kelvin’s assertions about the age of the earth (though there were more general rebuttals to the imperialism of physicists). Rather, it was Darwin in particular because of his adherence to phyletic gradualism who refused to bend the knee! All I can say is that Gould has made Charles Darwin into quite the ultra-Darwinian to this point….

Comments

  1. #1 Chris Rowan
    February 14, 2008

    Gould claims that the reality is that most geologists were satisfied with 100 million years…

    It would probably be more accurate to say that 100 million years was within the rather large range of ages proposed by geologists (based on calculations involving sedimentation rates or ocean salinity), although I’m fairly sure that it was towards the low end of the spectrum. However, it is certainly the case that Kelvin’s calculations gave those lower estimates a certain amount of additional respectability.

  2. #2 razib
    February 14, 2008

    It would probably be more accurate to say that 100 million years was within the rather large range of ages proposed by geologists (based on calculations involving sedimentation rates or ocean salinity)

    well, from the chapter gould makes it seem as if geologists had little genuine calculational sense of the age of the earth back then….

  3. #3 Chris Rowan
    February 14, 2008

    In the sense that they weren’t trying to make calculations, or that the methods that they were using were (from our modern perspective at least) flawed?

  4. #4 razib
    February 14, 2008

    In the sense that they weren’t trying to make calculations, or that the methods that they were using were (from our modern perspective at least) flawed?

    probably more the latter. the impression i got from reading the chapter is that the 95% intervals might go across orders of magnitude….

  5. #5 Caledonian
    February 14, 2008

    Rather like our estimates of “the age of the universe” today.

  6. #6 John J Emerson
    February 14, 2008

    This is the theme of Gould’s book “Time’s Cycle, Time’s Arrow”, which I recommend.

    The choice between catastrophism and uniformitarianism was not scientifically decidable at the time it was happening, and strikes me as an instance when a decision is made philosophically — or from a positivist point of view, arbitrarily. The opposition to catastrophism wasn’t mostly based on any reasonable or scientific assurance that there had been no catastrophes, but above all in order to exclude multiple Christian creationist attempts to explain everything away with ad hoc conjectures. For a lot of scientists it was central to their work, but it was a working assumption rather than a scientific result, and that distinction tends to be forgotten in scientific explanation.

    A second case close to the hearts of GNXP readers would be the rejection of human biological difference attributed to Boas: it was devised to exclude racist and physical-anthropological typologies of culture which were genuinely worth excluding, since they explained all cultural differences simply by assuming that all human groups are races, without any knowledge of their genetics or genetic history or of the mechanisms by which traits like “laziness, sullenness, and dirtiness” were genetically transmitted. (Note to Finn-bashers: those adjectives come from a British amateur anthropologist’s study of the Finnic peoples of Russia, for example the Mordvins.)

    The formation of the “channeled scablands” of E. Washington by the Lake Missoula floods is an example of a quite reasonable catastrophic explanation whose acceptance was impeded by ingrained uniformatarianism.

    Anyone who visits Missoula can see the old shorelines of Lake Missoula on the hillsides far above the city. There are many of them at many different levels and they’re visiually very evident.

    http://en.wikipedia.org/wiki/Channeled_scablands

    http://www.spokaneoutdoors.com/scabland.htm

  7. #7 John J Emerson
    February 14, 2008

    I meant to write “that distinction tends to be forgotten in scientific education“. The “fundamental principles of science” people learn at the beginning are sometimes results and sometime preliminary assumptions.