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Wednesday, December 02, 2009

Comparison and Adaptation

As most of you know, Richard Dawkins is not a fan of the Spandrels paper by Gould and Lewontin [A Critique of the Adaptationist Programme]. A reader has alerted me to a comment that Richard Dawkins posted on Jerry Coyne's blog.

Dawkins said [I was there ...].
I was there (one of the speakers) at the London meeting of the Royal Society, where the Spandrels paper was first presented (by Gould; Lewontin didn’t come). Before Gould spoke, the talk by Clutton-Brock and Harvey substantially anticipated the Spandrels paper and undermined its central thesis. All of us were eager to hear how Gould would deal with Clutton-Brock and Harvey’s devastating critique of what they guessed (from previous publications) he would say. In the event, Gould totally ignored Clutton-Brock and Harvey, and gave his prepared paper, playing for horse laughs from the gallery, as if nothing had happened. It was the beginning of my disillusionment with Gould, whom I had previously respected. Please, if you read the Spandrels paper, look first at the Clutton-Brock and Harvey paper, in the same volume published by the Royal Society, 1979.
I had not heard of this paper by Clutton-Brock and Harvey and I'm not familiar with their work. Here's the reference and the abstract—it doesn't look to me like a devestating critique of Gould and Lewonton's paper.

Clutton-Brock, T.H. and Harvey, P.H. (1979) Comparison and Adaptation. Proc. R. Soc. Lond. B 205:547-565. [doi: 10.1098/rspb.1979.0084]
It has sometimes been suggested that the term adaptation should be reserved for differences with a known genetic basis. We argue that adaptation should be defined by its effects rather than by its causes as any difference between two phenotypic traits (or trait complexes) which increases the inclusive fitness of its carrier. This definition implies that some adaptations may arise by means other than natural selection. It is particularly important to bear this in mind when behavioural traits are considered. Critics of the 'adaptationist programme' have suggested that an important objection to many adaptive explanations is that they rely on ad-hoc arguments concerning the function of previously observed differences. We suggest that this is a less important problem (because evolutionary explanations generally claim some sort of generality and are therefore testable) than the difficulties arising from confounding variables. These are more widespread and more subtle than is generally appreciated. Not all differences between organisms are directly adapted to ecological variation. The form of particular traits usually constrains the form or value that other traits can take, presenting several obstacles to attempts to relate variation in morphological or behavioural characteristics directly to environmental differences. We describe some of the repercussions of differences in body size among vertebrates and ways in which these can be allowed for. In addition, a variety of evolutionary processes can produce non-adaptive differences between organisms. One way of distinguishing between these and adaptations is to investigate adaptive trends in phylogenetically different groups of species.


  1. Both Clutton-Brock and Harvey are very influential evolutionary biologists. Both come more from an ethological background than a molecular one, so that's why you might not have heard of them. They were among the first to use the comparative method as a means to assess and/or find adaptive patterns in mammals, mostly primates. Since then, Tim C-B has moved on to study different animal populations in a long-term context. He's among the best behavioral ecologists out there, in my opinion. Paul Harvey went onto to study the theory of the comparative method, among other things, and his book "evolutionary biology and the comparative method" continues to be influential. His recent work essentially uses phylogenetic methods to probe different topics such as disease risk, language, etc. Individually or as coauthors (together and with others) they probably have about 65+ Nature and Science papers.

    I just re-read their paper based on Dawkins suggestion, it is good and they are not rampant adaptationists, rather they just take the approach that if something is an adaptation, let's figure out ways to test it. They didn't critique Gould/Lewontin's paper, rather they just showed, in a similar fashion to Gould/Lewontin, why not all traits should be deemed adaptations. They don't word their arguments as flowery as Gould/Lewontin and hence the latter authors are often given credit for calling attention to rampant adaptationism even though similar arguments were given by C-B/Harvey at the very same conference.

  2. It seems like a reasonable paper, but I don't see how it demolishes the Gould-Lewontin argument. As for Dawkins, he seems to be — as usual — concerned only with assimilating every conceivable criticism with his worldview, which turns it into unbearable mush, and makes it unfalsifiable.

  3. Oh Dawkins. He seems much less gentlemanly towards critics from 'his side' (ie, sanER people) that towards opponents of evolution (although, arguably he doesn't exactly shine there either). There was a fun thread on his forum where he was scolded (by biologists) for a repeatedly careless use of the word 'random', and his response to the criticisms was not quite warm and welcoming.

    In a way, this puts some of the potentially good views and theories that he supports and writes about into a bad light, and some people begin to shun those views just because of their dislike towards Dawkins. I tend to be still partial towards the gene being the principal unit of selection (with higher layers being less and less potent in terms of explanation), and quite like the idea of memetics, although NOT IN DAWKINS' RENDITION thereof. And it's really annoying to always have to announce the latter part as a disclaimer, as the critics of memetics often begin with: "Dawkins was wrong about blah and missed blah and has a big ego". Grrr, way to wreck a potentially greay idea!

    But his little comment about neutral evolution being of importance only to those annoying nitpicky molecular biologists still stings. And I'm not even a molecular biologist. He better appologise for that comment eventually, btw. Molecular and cell biology are the future of evolutionary theory. And its present, in fact. Ha!

    Just had to rant about Dawkins. Feel free to ignore and carry on... >_>

  4. Thanks to rich lawler for some more meat re the C-B and H article, which I was hoping for in the original post, frankly.

  5. There was a fun thread on his forum where he was scolded (by biologists) for a repeatedly careless use of the word 'random', and his response to the criticisms was not quite warm and welcoming.

    What do you mean "was"?

    The thread is still very much active, although Dawkins only occasionally reappears to repeat his unmodified, original assertion. Basically, the issue isn't so much that Dawkins uses "random" in a certain way that is intelligible to laypeople; it is rather that he uses "random" exclusively in that way and refuses to concede that there may be other more percise usages that are commonly understood by researchers in the field.

    Dawkins' exchange with Larry in the comments section of "Dawkins on Chance" here on Sandwalk is emblematic of the above issue. Essentially, Dawkins insists that "interesting" evolution is adaptation, that adaptation is non-random, and that it is therefore appropriate to say "[i]f evolution worked by chance, it obviously couldn’t work at all". In fact, Dawkins posited this argument despite the fact that Larry clearly pointed out that genetic drift is random, that Dawkins' conflation of natural selection and adaptation with the entirety of evolution is exactly why Dawkins is often called an "adaptationist" (with the most unflattering connotations attached) and that asserting that evolution is not random for the sake of contending with creationists (the people who have a vested interest in not understanding evolution)accept hinders the understanding of evolution by people who are actually interested in underastanding evolution. In other words, what is at issue on the thread on the Richard Dawkins Forum is not that Dawkins is necessarily incorrect for using "random" in a nontechnical sense when contending with creationists; it is that Dawkins doesn't seems to distinguish between those informal contexts involving evolution deniers from the slightly more formal contexts involving evolution acceptors.

    That being said, I think it would be best if the comment on the aforementioned thread were kept to a minimum here as the are only tangential to the topic of the entry. If there are people who would like to discuss the topic of the RDF thread, they can either post on the thread itself or prevail upon Larry to write an entry that is more germane to the thread topic.