I think Stephen Jay Gould would be appalled

By Razib Khan | July 24, 2006 10:35 pm

I am a little unsure whether this article in The Washington Post titled And the Evolutionary Beat Goes On . . ., beginning with the sentence “Stephen Jay Gould would have been pleased,” is a subtle joke or not. The journalist has a science background, and has even covered the evolution “controversy,” but that doesn’t really prepare you to dive into the brand new world of evolutionary genomics.
Here is the short of it. First, biases on the table, to say that I am not a Gouldian is charitable. I would argue that evidence of recent human evolution and diversification seems to be positively un-Gouldian. Here is the Wiki summary of Gould’s ideas in Gould’s words:

A new species can arise when a small segment of the ancestral population is isolated at the periphery of the ancestral range. Large, stable central populations exert a strong homogenizing influence. New and favorable mutations are diluted by the sheer bulk of the population through which they must spread. They may build slowly in frequency, but changing environments usually cancel their selective value long before they reach fixation. Thus, phyletic transformation in large populations should be very rare-as the fossil record proclaims. But small, peripherally isolated groups are cut off from their parental stock. They live as tiny populations in geographic corners of the ancestral range. Selective pressures are usually intense because peripheries mark the edge of ecological tolerance for ancestral forms. Favorable variations spread quickly. Small peripheral isolates are a laboratory of evolutionary change.

As the Pritchard suggests Gould’s work is somewhat orthogonal to what he and Lahn are studying, in sum Gould was focused on meta-taxa level macroevolutionary patterns and trends, while the human evolutionary genomics that is being reported is more species level and microevolutionary. But Gould’s dismissal of the power of alleles to sweep to fixation within large populations via deme-to-deme networks seems wrong, or at least the skepticism should be mitigated (selection coefficients are nasty little things and I am not positing a world of “Ideal gas laws” a la Fisher). Additionally, the evolution that Lahn and Pritchard are detecting is happening at the center of the action of our species’ range, not in small isolated populations. My understanding is that Gould emphasized the power of stabilizing selection in large populations, but stabilizing is not how you would describe the dynamics that are coming out of evolutionary genomics, the rate of change and the directionality are explosive and almost chaotic, scaling adaptive landscapes and shooting into multiple dimensions. Additionally, Gould was most definitely not a “selectionist,” if that means anything, but the article mentions selection nearly a dozen times!
From a Gouldian perspective we as a species are most definitely not in stasis, we’re a missle of allele frequencies dancing through gene space. If you want to view it through a macroevolutionary lens we were on the cusp of speciating! Because of transcontinental travel that is probably not going to happen, at least for now (population to population gene transfer has a way of quickly blocking differentiation of coadapted gene complexes). But the big elephant in the room is that the possibility that evolution has been “adapting different groups to the particulars of their ecological niches” renders Gould’s assertion that “Human Equality Is a Contingent Fact of History” moot. Physical equality implies equivalence, but human populations are not equivalent in their adaptiveness to various environments. This is why I have focused on The Andaman Islanders, these people render the perception of similarity shockingly deceptive, in particular because this population seems to die in the presence of Eurasians who blithely transmit their “super bugs” to them. Gould was wrong, the future does not belong to small isolated populations buffeted by stochastic contingency, it seems that the mass action of mutations driven by positive selection at the demographic center is where we should look.
Postscript: If you want to know what Lahn and Pritchard are doing, you need to survey to W.D. Hamilton, R.A. Fisher and Sewall Wright’s work. Much of recent human evolution seems driven by immune response, likely in a “Red Queen” manner as conceived by Hamilton. Additionally, the power of large populations to make drift less important and generate new mutations is a Fisherian insight. Finally, as the next level of granularity in this work proceeds I believe you will see some of the importance of substructure in a manner that Sewall Wright would have recognized. Gould’s project was to bring paleontology to an equal footing with genetics in the study of evolutionary science, but evolutionary genomics brings empirical wealth which can be viewed through a classical theoretical population genetic lens.

  • http://scienceblogs.com/evolgen RPM

    That’s just a really poorly written article.

  • gc

    But Gould’s dismissal of the power of alleles to sweep to fixation within large populations via deme-to-deme networks seems wrong
    Gould was a moron who tried to write a book on evolution without dealing with allele frequencies. He avoided allele frequencies, of course, both because of mathematical inadequacy and ideological aversion to the central point of allele frequencies: that populations vary genetically. Unlike his intellectual “big bro” Lewontin, who at least had the technical skills to lie confusingly — to lie with panache if you will — Gould was way out of his depth when it came to talking about anything other than snails.
    No surprise that Gould’s body of writing was one long confused mishmash of wishful thinking, intentional propaganda, and outright stupidity. Sadly, this fool and charlatan, this ideological Torquemada, is still revered as a “great thinker” among those who know no better.
    But not for long… :)

  • http://evomech3.blogspot.com/ John Latter

    If anyone is interested, the PLoS Biology paper the Washington Post refers to can be found here:
    A Map of Recent Positive Selection in the Human Genome
    John Latter / Jorolat
    Evolution Research

  • bioIgnoramus

    “one long confused mishmash of wishful thinking, intentional propaganda, and outright stupidity.” For what it’s worth, that was my assessment too, and I really do know bugger-all about genetics. But when a man writes as if he wants you to think him a chump, it seems rude to demur.

  • http://akinokure.blogspot.com Agnostic

    I assumed it was either a thumb-nosing joke, or that someone he interviewed impressed upon him that this is true, so that printing it would be a kind of practical joke on the part of the scientist involved. NB: I make no claims about who this person might be, just saying it’s likely.

  • shhiggins

    Golly, gc proclaims Gould an ‘ideological Torqemada’, while bioIgnoramus claims to know ‘bugger-all about genetics’!
    As David Spade so eloquently put it – and you are…?

  • http://www.scienceblogs.com/gnxp razib

    New and favorable mutations are diluted by the sheer bulk of the population through which they must spread. They may build slowly in frequency, but changing environments usually cancel their selective value long before they reach fixation.
    well, as i note here, it is large populations that selection tends to operate with a free hand. so the quote kind of makes him seem dumb. *shrug*

  • http://adversecity.blogspot.com/ Oran Kelley

    gc writes:
    “He avoided allele frequencies, of course, both because of mathematical inadequacy and ideological aversion to the central point of allele frequencies: that populations vary genetically.”
    Then how did he expalin human phenotypic variation that maps directly on to geography?

  • http://adversecity.blogspot.com/ Oran Kelley

    Could it be, perhaps, that Gould, in fact, acknowledges that populations vary genetically. That pretty much everyone admits that.
    Could it be that someone suggesting that Gould DIDN’T acknowledge this point would be a tiresome crank?
    Someone who, say, who is obsessed with compelling everyone to believe that blacks and hispanics are genetically inferior to whites and asians?
    That sort of person would certainly hate Gould, and would probably say just about anything to discredit him, don’t you think?

  • http://www.rishon-rishon.com David Boxenhorn

    It seems to me that Gould’s comment accurately describes the situation with Ashkenazis, taking “periphery” to mean some degree of genetic isolation plus a “peripheral” habitat.

  • http://www.scienceblogs.com/gnxp razib

    yes, some of it is there, but will the ashkenazi jews lead toward a future speciation event? the key is the emphasis one places on particular processes. e.g., fisher dismissed drift and non-additive genetic variance not because it didn’t have an evolutionary effect, but because over the long term it didn’t have a net directional effect (in his estimation).

  • http://www.rishon-rishon.com David Boxenhorn

    but will the ashkenazi jews lead toward a future speciation event?
    Given enough time and stable habitats, I would suppose so.
    It does seem reasonable to me that in large populations additive effects would be more evolutionarily important, relative to non-additive effects, than in small populations. Put another way, large populations take advantage of the large variety of alleles, while small populations can more easily take advantage of combinations of alleles.
    There must be some simulations of this already out there…

  • bernarda

    gc goes into a diatribe against Gould. What for? Science is full of researchers who have made mistakes–and I am not here admitting to any particular mistake by Gould. That is what science is about.
    Other researchers examine the evidence and the theories and eventual errors are discovered. Saying that someone is a moron because perhaps they made a mistake is not very scientific.
    In past times many researchers made mistakes because they were just working with the knowledge of their time. It would add nothing to the debate to call them morons today.
    gc has discredited himself.

  • http://scienceblogs.com/gnxp razib

    the problem with some of gould’s assertions (like the ones above) is that they seem counter to basic population genetics. this isn’t an experiment or hypothesis gone wrong. the power of selection larger populations was clear long before gould’s time, it isn’t like they didn’t have drosophila to use as experimental subjects.

  • http://adversecity.blogspot.com/ Oran Kelley

    “Here is the Wiki summary of Gould’s ideas in Gould’s words”
    Actually, this is introduced as Gould’s 1977 summary of Mayr’s ideas on the topic. Does this correspond exactly to Gould’s ideas? And wasn’t Mayr’s speciation theroy pretty well-accepted in 1977?
    J. Mallet:
    To see just how much has changed, consider what
    experts were saying until recently. Coyne (1994), for
    example, listed four major achievements due to Ernst
    Mayr since the 1940s. These were: (1) an appreciation of
    the reality of species (as compared with, say, the
    unreality of subspecies or genera); (2) the reproductive
    isolation de®nition of species (the `biological species
    concept’); (3) the generality of allopatric speciation; and
    (4) founder-effect speciation. Coyne (1994) argued that
    Mayr’s fourth achievement, the founder effect, was
    probably incorrect, but regarded the other three as
    completely in tune with the current view of speciation.
    What is extraordinary about this list is that all these
    `achievements’ are now, only 7 years later, rejected by
    major groups of evolutionary biologists. Softening on
    points (1) and (3*) are found today even in papers coauthored
    by Coyne himself (Kliman et al., 2000; Turelli
    et al., 2001). The opinions under attack date from the
    1930s to the 1950s, and are identifed strongly with
    Theodosius Dobzhansky and Ernst Mayr; however, virtually
    all evolutionary biologists and most textbooks
    supported these ideas until the late 1980s.

  • http://adversecity.blogspot.com/ Oran Kelley

    Thought I remembered Gould coming back to this issue: he actually talks about it quite a bit in his Structure of Evolutionary Theory (2002):
    “We took Mayr’s allopatric theory (as expressed in his treatise of 1963, deemed ‘magesterial’ by Huxley), and tried to elucidate its impled expression when scaled on to geologic time. . . . We chose Mayr’s formulation because his allopatric theory represented the most orthodox and conventional view of speciation then available. . . .I recognize, with 30 years of hindsight, that our original assessment of Mayr’s theory and of professional consensus may have been both naive and overly dichotomous . . .” (779)
    “Eldridge and I have often been asked what we think of sympatric speciation, or of various models, like polyploidy, for rapid origin even in human time. We do not mean to be evasive or obscure in our assertions of agnosticism.” (Going on to explain that his own primary interest–punctualted equilibrium–is reasonably compatible with any fast path to speciation.) (780)
    “I can claim no expertise in this aspect of neontological evolutionary theory, but I certainly acknowledge . . . the revised consensus of the past twenty years that has challenged this body of thought, and rejected any general rationale for equating the bulk of evolutionary change with events of speciation in small populations, or with small populations in any sense. . . . most evolutionists now view large populations as equally prone to evolutionary transformation. . . . (I do, however, continue to wonder whether the Mayrian viewpoint might still hold some validity, and might now be subject to overly curt and confident dismissal.)” (797-8)


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com


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