pz

Ah, you see, but you do not understand. That is the adaptationist paradigm, exactly as Gould describes it. Gould does not claim that adaptationists deny drift, neutral theory, etc. -- they acknowledge it, embrace it, and then go on to say it's not interesting or important.

Gould does not deny the importance of selection in forming finely-tuned functional structures, like the eye. Where he differs, though, is in his pluralism: those other, nonadaptive elements of evolutionary theory are as important or maybe even more important than adaptation. You cannot answer why chimpanzees and humans are different by pointing at the eye, for instance; it may be a fine explanation for why things work, but since all life on the planet has had the same long history of relentless selection, it's an extremely unsatisfying explanation for diversity.Then you should stop reading Dawkins. Although he has made some concessions from his painfully wrong stance in The Selfish Gene with his book, The Extended Phenotype, he's still pretty much the same ol' genecentric adaptationist he's always been. That's actually extremely ironic, since one thing that is extremely clear in his books is that he doesn't have a clue about how you get from genes to organisms.

I do agree on the general clarity of the writing, though. Dawkins has a knack for clean, sharp writing. Gould always had an eye for the complication, the diversion, the odd tangent, and his writing suffered for it. His last book has sections that are almost intolerably prolix (although I guess he does have a good excuse -- the editing was abbreviated, of necessity).

I see it as a difference in their view of life, too. Dawkins sees simple principles underlying biology. Gould saw rich, messy, ramifying multitudes of forces.

Personally, I find the latter view far more compelling, and a more accurate picture of real biology.

Doubting Didymus

Regarding Dawkins specifically, I think that this is almost entirely true. However, going by his most recent writings, I'd say it's more accurate to say that he accepts drift, neutral theory, drift, so forth, AND acknowledges its interest and importance, before going on to focus only on other things (namely Darwinism). I don't think you can fault Dawkins on that much other than a too-narrow outlook on biology as a whole.

I agree on all counts. However, regardless of the relative importance in biology of adaptationist / nonadaptationist elements, it can hardly be denied that adaptations themselves are both common enough and unique enough to deserve a special explaination. I strongly believe that adaptations naturally spawn specific questions in human minds, namely "How did this get here?", and, "No really, how the hell did this get here?". When you're trying to explain modern diversity, or the differences between humans and chimps, or any specific component of any organism, or especially an element of our psychology, then adapations-by-selection is an obviously inneffectual approach. When you're trying to explain the building up of complex and hardy organisms that are fitted to their environment like keys to locks, which is the thing that most immediately cries out for an explaination (especially to laypeople), then a focus on adaptation is not just forgivable, it's justified and even neccesary.

But Dawkins's gene centrism is specifically aimed, not universal. I might be wrong, but I'm quite sure Dawkins isn't arguing for a gene centric view of development, or a gene centric view of any physical biology. Gene-centrism as I understand it applies only to selection, which in turn applies only to adaptation. When restricted entirely to selection in this way, I still think it's an accurate perspective. There is no candidate in organisms to display heritability, mutability, and differential replication efficacy other than the gene.

I can't agree more with this last sentiment. However, I'm not sure Dawkins is even trying to 'explain life'. I think he makes it very clear on several occasions that he is only trying to explain adaptation. We can, and maybe should, fault Dawkins for focusing too much on one aspect of the theory, but given that that is his focus, I, for one, can not fault his explaination. I say this tentatively, because there are moments in some of the articles in A Devils Chaplain where he seems to be stepping outside his circle of expertise.

I'm thinking primarily of a small diversion in Darwin Triumphant where he describes the evolution of segmentation via a macromutation, imagining the newly segmented beast at a severe disadvantage due to its disastrous change, barely surviving birth. This mutation is supposed to happen to coincide, by luck, with the opening of an easy ecological niche, so that the mutant is not placed under too much pressure. He then imagines it being 'corrected' by gradual selective steps towards being an organism capable of competing for true in a genuinely difficult survival race, supposedly the normal state of an organism.

Something here just doesn't feel right. Something's being glossed over, something else ignored. This is something I will be keeping at the back of my mind for some time as I complete the rest of my study.

Oolon Colluphid

Well, I pretty much agree with DD, which means I pretty much agree with pz. I guess the problem is, what Dawkins happens to find most interesting is what I too find most interesting.

I’ve learnt most of my biology from fighting creationists, remember, and ‘adaptionism’ is not only the best tool for that, but also, the other factors in evolution’s widescreen picture generally do little -- while being relevant as far as science is concerned -- other than further muddy the already murky waters of the creationist mind. Basically, I focus on that which refutes creationism. So when creationists start arguing about how genetic drift cannot form what we see, then I guess I’ll have to take more notice of it!

Cheers, Oolon

pz

I don't understand this at all. Why would you let creationists define the terms of the discussion about evolution?

Secular Pinoy

My reading of Dawkins gives the impression that his gene centrism is more than explaining adaptation. He sees organisms' bodies as "vehicles" and "survival machines" for genes (which is definitely more than mere adaptation) , and his idea of how creatures make a living is synonymous with struggling/competing to pass their genes to the next generation. IOW, he's trying to explain life as merely the struggle of genes to propagate in the gene pool. It just so happens that these genes use their hosts' bodies as temporary receptacles and that most, if not all, the competition and survival actions of these bodies are reducible to genes. That's why he developed the idea of the Extended Phenotype, the so-called "long reach of the gene".

Doubting Didymus

Good points, but I think you may be confusing an attempt to explain why life is here at all (as opposed to never having occurred), with explaining things about those lifeforms. It's easy to think Dawkins is making grander claims than he actually is, mainly because he is constantly excited and writes so well that you can hardly help but become enthused by association.

However, I really think that Dawkinsonian gene centrism is only intended to apply to natural selection. When organisms are described as vehicles for heritable units, it is from the perspective of natural selection. In his lay writings, Dawkins makes a consistant effort to point out that gene centrism does NOT imply that the veiw of organisms as vehicles should influence the way we think about organisms as wholes, especially in the case of humans. It is only where natural selection sees through bodies to influence gene pools that the vehicle perspective is relevant. If Dawkins never says this directly, he ought to have, as I believe it is his personal intention.