Secular Pinoy

In Niles Eldredge's book Reinventing Darwin, the author makes a distinction between the so-called Ultradarwinists (Pan-Adaptationists, Gene-centric evolutionists, and Gradualists) and those like him, whom he calls Naturalists.

As someone who find pan-adaptationism to be narrow-minded and ultimately futile, gene-centrism misguided and gradualism inadequate to explain the diversity of life and the historical record, I feel alienated at times with most of the discussions in this forum.

So, is there anyone else here who is sympathetic with the Naturalist paradigm? Those who can't stand the gene-worship? Those who shudder at the over-reliance on adaptationist just-so stories? Those who find that most evolutionist (like R. Dawkins), while accepting the basic outline of the complex nature of the fossil record, still nonetheless tell of evolutionary scenarios that are patently linear and gradual? Those who know there is more to speciation than just the gradual march of gene mutation (microevolution writ large, as they say)?

Baloo

Could you perhaps be more specific, maybe refer to a "best case" of the Naturalist paradigm wherein a speciation occured for which you "know" it couldn't have come about by mere selective pressure acting on the genetic variation in a given population? I guess I'm just asking for a concrete, real-world observation better explained by the "Naturalist paradigm" than by neo-Darwinism as portrayed by Dawkins and the like.

lpetrich

I wonder what Secular Pinoy is asking for -- someone to be Stephen Jay Gould's successor?

Boro Nut

Most German bathers I've encountered.

tronvillain

Perhaps you could link to something by a "naturalist"? So far I do not think I am going to be a big fan.

KC

The differences over speciation and the fossil record between Dawkins and Eldredge/Gould have been overblown, IMNSHO. For example, Eldredge admits that punk eek fits the classic allopatric speciation model, and Dawkins has stated that as well. Sounds like a storm in a teacup to me.

Cheers,

KC

Oolon Colluphid

Agree completely. Dawkins would doubtless say that it was Gould and co who had been doing the overblowing... and has described the version of 'gradualism' that punk eek is opposed to as 'constant speedism' -- which nobody believed anyway.

DT

Oolon Colluphid

Okay... but I’m at a loss as to what the distinction might be. Perhaps as you’ve read the book, you can tell us how Eldredge defines the two ‘camps’?

And what might this "pan-adaptationism" be...? That everything has an adaptive purpose, perhaps? If so, let me introduce you to a certain Dr Pangloss.

I consider myself a run-of-the-mill adaptionist. And I’m fairly sure that the likes of Dawkins and Maynard Smith would too. (JMS once noted that the difference between himself and Gould was that “I’m an adaptionist all the time, whereas Steve is only adaptionist Mondays, Wednesdays and Fridays.”) So what is this “pan-adaptionism”, if I’m to be accused of it?

How? Need I remind you that ‘one should always keep an open mind, but not so open that your brain falls out’? What does this “pan-adaptionism” (which may turn out to be a straw man anyway -- see definition request above) miss?

Huh? Unless one is a creationist, one has to take as a base the fact that things have evolved. Now, of course there’s more to evolution than natural selection -- you do know that Dawkins, Ridley, JMS and co do know that, right? -- but natural selection, being selection, leads to adaptation (see page one of any evolutionary biology textbook). And it is what constructs all the interesting stuff -- eyes, ears, wings and brains.

So again: what alternative do you know of? What does taking the fact of adaption as a basis for enquiry miss? For rather than futile, it looks to me to be a pretty damned effective way of tackling things.

What do you mean by it, and how? I smell another straw man. One that’s been out in the rain and has gone a bit mouldy, perhaps.

Ah. So... you’re a creationist... or a saltationist...?

What is this ‘gradualism’ of which you speak?

Well you would, since you don’t seem to have grasped what you’ve been reading. (I’m not being nasty: I feel the same if ever I look in on BC&A or EoG.) If you understood the basics of evolutionary biology, I expect these philosophical obstacles would dissipate. Try getting hold of Futuyma’s textbook Evolutionary Biology, or if that’s a bit daunting (it is!), try Maynard Smith’s The Theory of Evolution.

To put it simply: gradualism is genetic gradualism, in that genes have to meke it into future generations to matter to evolution. Living things are only here living because none of their ancestors died childless.

But this says nothing about the pace of evolution, the impact of the environment on what lives and dies (and over macroevolutionary timescales, you get plenty of environment), nor even much about the phenotypes involved.

All that is gradual is the manifest necessity for things to have offspring if they want grandchildren, for there to be generation-to-generation continuity.

Erm, pending the definition of that, I’ll stick my neck out and say that I had thought I was a ‘Naturalist’. I’m sure as hell not a supernaturalist...

Ah, so you think that because genes are a damned useful thing to study, and encode details of how to make a body, and are known to mutate producing different bodies, and can be used to measure relatedness, and so on... you think that evolutionary biologists think that’s all there is to it? I’m pretty certain neither Dawkins nor I have ever worshipped genes at all.

In the popular science books? Or in the real literature?

It’s only a just-so story if it is unverifiable. But if it doesn’t make testable predictions, it isn’t science full stop. If it does make predictions, then such ‘stories’ are just like any other hypothesis.

I shall ignore that ridiculous remark untill you’ve bloody well gone and read some Dawkins. You know not what the blue hell you’re talking about. (Hint: what is Dawkins’s purpose in writing ‘popular’ books?)

Ah, knowledge. How cometh you by this certainty all of a sudden?

You can... no DT, don’t... ah to hell with it... you can define ‘species’ and list a few mechanisms of speciation, yeah? In that list you might include -- as does eg the full-time adaptionist JMS -- something called ‘allopatric’ speciation.

Hmmm. Let me get this straight... Gene mutation = microevolution; pan-adaptionist macroevolution = merely more of the same over a much longer timescale. Pan-adaptionists therefore have never heard of earthquakes, volcanoes, meteorite impacts, flooding, drying, orogenesis, the formation of islands, and the rest, Oops. Despite being a ‘supporter’ of Dawkins, I can’t be a pan-adaptionist gene-worshipper, because I seem to have heard of them... Say, maybe they might affect the pattern of life over geologic timescales too? D’you think?! Hey, maybe they might affect which genotypes make it to the next generation!

TTFN, DT

pz

Definition by example follows...
Yep, that's classic panadaptationism. Pay a little lip service to other things, but always stick to the claim that all the interesting stuff is a consequence of adaptation.
Well, we know that the majority of the genomic differences between any two species are going to be nonadaptive. That suggests that you are missing a rather substantial chunk of the story by focusing on adaptive change.

We know that many features of organisms that we take for granted, such as sex and altruism, are difficult to explain within an adaptationist framework.

We know that genocentric adaptationism of Dawkins' sort is not going to be adequate to explain most metazoan characters, which require the coordinate action of multiple genes.

We also know that most genes are pleiotropic to a ridiculous degree. A modification to one character that results in an adaptive change is going to have a hundred side effects. Most features will be spandrels, not the direct result of selection, so it is a classification error to assume that all the interesting stuff is adaptive.

Adaptationism focuses on evolution as a process of refinement, of 'climbing mt. improbable'. The adaptationist model of evolution would be a sculptor, patiently chiseling away at a population, slowly shaping it closer to an optimal form. Unfortunately, evolution is looking more and more like a found artist, slapping together geegaws in the process of bricolage.

Adaptationism says little about the origins of novelty, because it can't -- novelty by its nature is saltational. It is a great tool for describing stasis, which makes it very useful, since that is the state in which species spend the majority of their lifetime.

There are alternatives to adaptationism. Gould would have called himself a pluralist, which makes JMS's comment rather funny -- he clearly misses the whole point. Gould believed in adaptation all the time; it's just that he also recognized other forces that are just as important if not much more important, forces that JMS excludes from serious consideration all the time.

There are complexity theorists like Stuart Kauffman and Brian Goodwin, who see sophisticated order as a commonplace consequence of the natural laws of the universe, with many biological phenomena requiring no explicit imposition by selection to arise.

There are developmental systems theorists like Oyama and interactionists like Lewontin, who would say that "everything is the way it is because it got that way", and emphasize the evolution of process over the evolution of solutions. They tend to minimize the dichotomy between species and environment that is absolutely central to the adaptationist paradigm.

So yeah, there are good, interesting, fruitful alternatives to adaptationism, which also hold promise of being better able to explain many features of our organic world.

pz

Over here. I think you are looking for me.