Fodor on Natural Selection

Philosopher Jerry Fodor offers up the latest example of a familiar genre: essays declaring the forthcoming demise of natural selection, coupled with very little in the way of supporting argument. He is writing in the London Review of Books. There's quite a bit I find wrong with Fodor's essay. In this post, however, I will focus solely on what I take his main argument to be, and explain why I find it inadequate.

Fodor writes:

In fact, an appreciable number of perfectly reasonable biologists are coming to think that the theory of natural selection can no longer be taken for granted. This is, so far, mostly straws in the wind; but it's not out of the question that a scientific revolution - no less than a major revision of evolutionary theory - is in the offing. Unlike the story about our minds being anachronistic adaptations, this new twist doesn't seem to have been widely noticed outside professional circles. The ironic upshot is that at a time when the theory of natural selection has become an article of pop culture, it is faced with what may be the most serious challenge it has had so far. Darwinists have been known to say that adaptationism is the best idea that anybody has ever had. It would be a good joke if the best idea that anybody has ever had turned out not to be true. A lot of the history of science consists of the world playing that sort of joke on our most cherished theories.

We should also note Fodor's version of “the theory of natural selection:”

But Darwin's theory of evolution has two parts. One is its familiar historical account of our phylogeny; the other is the theory of natural selection, which purports to characterise the mechanism not just of the formation of species, but of all evolutionary changes in the innate properties of organisms. According to selection theory, a creature's 'phenotype' - the inventory of its heritable traits, including, notably, its heritable mental traits - is an adaptation to the demands of its ecological situation. Adaptation is a name for the process by which environmental variables select among the creatures in a population the ones whose heritable properties are most fit for survival and reproduction. So environmental selection for fitness is (perhaps plus or minus a bit) the process par excellence that prunes the evolutionary tree.

Now, these are a confusing couple of paragraphs. They seem to conflate several key ideas for the purpose of creating a straw man. First, I assume that by “innate properties” of organisms Fodor means their genetic endowments, as otherwise I can make no sense of this at all. Natural selection is a process that affects gene frequencies in populations of animals over many generations. If Fodor has in mind innate properties that are not genetic, then I do not think that natural selection is offered by anyone as an explanation for them.

Second, I am not aware of anyone who seriously argues that natural selection is the sole explanation for the innate properties of organisms. Fodor gives no examples of anyone actually defending that view. The names usually associated with adapationism, such as Richard Dawkins, George Williams, Daniel Dennett, and John Maynard Smith certainly do not (or did not in Maynard Smith's case) believe any such thing. This looks like a pretty blatant strawman to me.

But the really egregious part of these paragraphs is the conflation of natural selection as the explanation for adaptations on the one hand, with the idea of adaptionism on the other. The former is, as far as I know, entirely unquestioned among biologists, while the latter is a derogatory term used by some critics (Stephen Jay Gould most famously) to describe an approach to certain biological problems thought by the critics to rest on faulty assumptions.

Fodor is, presumably, referring to Daniel Dennett when he talks about Darwinists saying that “adaptationism is the best idea anyone has ever had.” The trouble is that neither Dennett nor anyone else has ever said any such thing. Here is the full quote, from Dennett's book Darwin's Dangerous Idea:

Let me lay my cards on the table. If I were to give an award for the single best idea anyone has ever had, I'd give it to Darwin, ahead of Newton and Einstein and everyone else. In a single stroke, the idea of evolution by natural selection unifies the realm of life, meaning, and purpose with the realm of space and time, cause and effect, mechanism and physical law.

Elsewhere in his essay Fodor quotes the latter part of this statement, for the purpose of ridiculing it, albeit without crediting Dennett. So plainly he knows the full context of Dennett's statement. Either Fodor is guilty of an egregious misrepresentation of Dennett's views, or he has wrongly conflated “evolution by natural selection” with “adaptaionism.”

Whenever someone, especially a philosopher, starts claiming that there are major conceptual problems with natural selection or that selection is on its way out among biologists, I always like to bring it back to specific adaptations. The eye, for example. The usual account says that eyes evolved gradually through numerous intermediate steps, each one attainable from the one before by a chance genetic variation, with natural selection preserving the intermediate steps while waiting for the next variation to arise. That natural selection has such creative power is the really bold claim of Darwinian theory. If some reputable person is arguing that the usual account is wrong, not just in the details but in the fundamentals, then I will raise an eyebrow and listen with interest to what the fellow is saying.

But if the person is granting the basic accuracy of the usual account, and by extension accepting natural selection's role in crafting every other complex adaptation in nature, then I am afraid that whatever he is arguing for is something a great deal less than a scientific revolution. If you are conceding that natural selection is the explanation for complex systems, then you are automatically conceding that natural selection is the most important of evolutionary mechanisms.

In saying this I don't think I am merely expressing a personal preference for certain kinds of biological problems (explaining biological adaptations) over other kinds (explaining traits of organisms that are not obviously adaptations). I think it is fair to say that the main stumbling block in the acceptance of evolution, not just for creationists but for everyone, is the problem of complex systems. There's a reason Paley's argument was so convincing when he first devised it. Once you provide a naturalistic explanation for such complexity, everything else is a detail.

At any rate, I see nothing in this essay to suggest that Fodor is rejecting the usual account. He discusses some philosophical issues concerning the proper definition of the notion of “selection for,” but it looks to me like if you asked him where eyes come from, he would answer essentially like Richard Dawkins. For the record, I am not impressed by his arguments here (what he describes as “the conceptual issue” threatening the centrality of natural selection) but I will not address them here.

Fodor later turns to “the empirical issue:”

Even the hardest core Darwinists agree that environmental effects on a creature's phenotype are mediated by their effects on the creature's genes: its 'genome'. Indeed, in the typical case, the environment selects a phenotype by selecting a genome that the phenotype expresses. Once in place, this sort of reasoning spreads to other endogenous factors. Phenotypic structure carries information about genetic structure. And genotypic structure carries information about the biochemistry of genes. And the biochemical structure of genes carries information about their physical structure. And so on down to quantum mechanics for all I know. It is, in short, an entirely empirical question to what extent exogenous variables are what shape phenotypes; and it's entirely possible that adaptationism is the wrong answer.

This is a prelude to an argument that it is internal developmental constraints, as opposed to natural selection, that really drives evolution, but once again Fodor's phrasing is terribly confusing. “Adaptationism” is not a proposed answer to the question of the extent to which external, as opposed to internal, factors influence the phenotypes of organisms. Rather, it is an approach to biology that argues that in trying to explain the origin of some trait in an organism you should hypothesize that it is an adaptation and then use that hypothesis to formulate testable conjectures. Note that the hypothesis is the beginning, not the end, of the investigation, contrary to what some critics of adaptionism suggest. This approach has notched up far too many successes to be discarded cavalierly.

Presumably Fodor's point is that adaptationists accept a low standard of evidence in describing various traits as adaptions, thereby ignoring other possible mechanisms. He writes:

When you ask Darwin's question - why are phenotypes often similar? - you do indeed get Darwin's answer. But if you ask instead why it is that some phenotypes don't occur, an adaptationist explanation often sounds somewhere between implausible and preposterous. For example, nobody, not even the most ravening of adaptationists, would seek to explain the absence of winged pigs by claiming that, though there used to be some, the wings proved to be a liability so nature selected against them. Nobody expects to find fossils of a species of winged pig that has now gone extinct. Rather, pigs lack wings because there's no place on pigs to put them. To add wings to a pig, you'd also have to tinker with lots of other things. In fact, you'd have to rebuild the pig whole hog: less weight, appropriate musculature, an appropriate metabolism, an apparatus for navigating in three dimensions, a streamlined silhouette and god only knows what else; not to mention feathers. The moral is that if you want them to have wings, you will have to redesign pigs radically. But natural selection, since it is incremental and cumulative, can't do that sort of thing. Evolution by natural selection is inherently a conservative process, and once you're well along the evolutionary route to being a pig, your further options are considerably constrained; you can't, for example, go back and retrofit feathers.

That all seems reasonable on the face of it; but notice that this sort of 'channelling' imposes kinds of constraint on what phenotypes can evolve that aren't explained by natural selection. Winged pigs were never on the cards, so nature never had to select against them. How many such cases are there? How often does a phenotype carry information not about a creature's environment but about aspects of its endogenous structure? Nobody knows.

In the opening sentence of this quotation, Fodor is referring to common ancestry, not natural selection, as “Darwin's answer.”

Fodor is very taken with his winged pig example. His essay is titled, “Why Pigs Don't Have Wings.” And I agree that if the question is why we don't find various hypothetical phenotypes, then it is often implausible to say that at one time those phenotypes existed but then lost out in competition with other phenotypes.

But Fodor's question just is not one that biologists dwell on much. They're too busy trying to sort out the proper relationships among modern species, or trying to ferret out the intermediate steps of complex systems. They concern themselves with questions like, “BIllions of years ago there were no eyes. Today, there are lots of eyes. Where did those eyes come from?”

If the devotees of developmental constraints want to claim the lack of winged pigs as a victory for their side then they are welcome to it. The supporters of selection can still claim eyes, bird wings, flagellae, blood clotting cascades and every other complex system over which everyone gets so excited.

In addition to developmetnal constraints Fodor points to the possibility of linkages between certain traits. This is the spandrel idea popularized by Gould and Lewontin. The idea is that trait X might persist in a population not because it triumphed in Darwinian competition with various not X's, but because it is genetically linked with trait Y which itself was favored by selection. This, too, is hardly a new idea, and it is not one evolutionists inclined towards adaptationism have been ignoring.

In short, Fodor has rehashed some very familiar practical issues in teasing apart which parts of an organism are the products of selection and which parts arose from other evolutionary mechanisms. Yes, of course, it can be difficult to recreate precisely the evolutionary history of a modern species. But he has offered nothing to challenge the centrality of natural selection in explaining complex adaptations, and he certainly has offered nothing that augurs for a revolution in biology.

In the final paragraphs of the essay Fodor tells us what is really bothering him. Evolutionary psychology:

But I think there's also a moral about what attitude we should take towards our science. The years after Darwin witnessed a remarkable proliferation of other theories, each seeking to co-opt natural selection for purposes of its own. Evolutionary psychology is currently the salient instance, but examples have been legion. They're to be found in more or less all of the behavioural sciences, to say nothing of epistemology, semantics, theology, the philosophy of history, ethics, sociology, political theory, eugenics and even aesthetics. What they have in common is that they attempt to explain why we are so-and-so by reference to what being so-and-so buys for us, or what it would have bought for our ancestors.

From here Fodor dives into a litany of various evolutionary psychology explanations he presumably has seen somewhere or other. He is careful not to provide a single citation, which would make it possible to look into the details of the hypotheses he describes so callously. I suspect there's some serious oversimplifying going on here.

That aside, once again it is unclear what Fodor is suggesting. Is he saying that natural selection is not the primary explanation for why our brains have the structure and characteristics that they do? Does he think that such a complex, functional organ can come about by some mechanism other than natural selection? If he does, then I would like very much to hear his proposed explanation.

But it seems more likely that he is making the entirely conventional point that it is a difficult practical problem to tease apart which aspects of the brain were the targets of selection and which parts piggy-backed on those fitness enhancing traits. This, however, is not a claim that merits Fodor's melodramatic language about revolutions and the demise of natural selection.

Fodor's essay is quite long and I have only replied to a few brief excerpts. It is probably worth another blog entry discussing some of Fodor's more philosophical points. But for now it looks to me like Fodor has merely erected a familiar straw man version of adaptationism, and has rehashed a lot of cliched arguments against it. Worst of all, I find virtually nothing in this essay that is in any way new (a description of an interesting experiment on trait linkages in foxes being a notable exception), and nothing that comes close to justifying Fodor's strident language.

Fodor and Dennett have a history of tendentious disagreements. In one exchange, Dennett wrote of Fodor:

Now this really is absurd. Silly absurd. Preposterous. It is conclusions like this, built upon such comically slender stilts, that give philosophy a bad name among many scientists.

Based on this essay, I agree with Dennett's assessment.

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I insist: any person slightly literate about the genetics of adaptation knows what I am talking about. But truth machine seems not to accept the terms of the discussion.
He can suit himself.

By Alexander Vargas (not verified) on 16 Oct 2007 #permalink

why are my comment not pulling through? censorship? ALREADY?
scienceblogs suck

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

I don't know a thing about Mr Fodor but his understanding of biology seems to be very poor. And the language he uses is full of confusions. Couldn't he find another subject to get philosophical about?

By Christophe Thill (not verified) on 15 Oct 2007 #permalink

Yeah, even before you mentioned Dennett I was wondering if this was an extension of the feud. Everything I've read of Fodor's in the LRB in the last few years has come across as a bizarre, poorly argued dig at Dennett, even when the general argument he was making was sensible. The guy's gone off the deep end.

This one is all the more confusing because Dennett is perfectly open to developmental constraints being an influence on evolutionary outcomes. Darwin's Dangerous Idea was written before the evo-devo movement had really taken off, yet in its Library of Mendel analogy he explicity describes how the evolutionary search algorithm is constrained by its past results.

By Ginger Yellow (not verified) on 15 Oct 2007 #permalink

Drat, you beat me to this one! I'll probably do a write up anyway, given that Fodor is at Rutgers, but this was an excellent take down. I read another essay on his CV website entitled "Against Darwinism," but it was very incoherent and fraught with errors.

I'm not a biologist so excuse me if I ask a dumb question. Since when did anyone claim that natural selection had to select against something for it not to exist (the flying pig example)? I always thought natural selection worked with the changes that actually occurred in the genome. Its a trivial point to say that a pig needs more than wings to fly. What does that have to do with natural selection or adaptation?

I think Fodor's essay is a perfect example of what I will modestly call "Shallit's dictum":

Never bother listening to a philosopher over the age of 60.

Another example is Antony Flew.

By Jeffrey Shallit (not verified) on 15 Oct 2007 #permalink

I seem to remember getting in a long discussion over something Fodor had written in the "philosophy of mind" department. The gist of my argument was that you could only say the things he said if you were completely ignorant of computer science and statistical physics. I'll have to see if I can find that discussion again. . . .

For me this quote best captures the vacuity of his argument:

The crucial test is whether one's pet theory can distinguish between selection for trait A and selection for trait B when A and B are coextensive: were polar bears selected for being white or for matching their environment? Search me; and search any kind of adaptationism I've heard of. Nor am I holding my breath till one comes along.

So, what's his solution? That polar bear pigmentation was not selected for? Or what?

Well, some people (check the blog "Sandwalk") do acuse Dawkins and similar people of implying that any and all mutations necessary to produce whatever adaptation may best serve an animal at a given time will be available. Perhaps, but that particular implication was never apaprent to me when I read Dawkins' popular books.

Everything I ever read about evolution made it quite clear that some adaptations cannot develop in some animals, for the simple reason that the intermediate steps are impossible or detrimental, no matter how good the adaptation may be once it is fully developed.

I guess that some professional biologists just don't know high school biology...

By valhar2000 (not verified) on 15 Oct 2007 #permalink

Jason, you have a seemingly endless fountain of patience. I applaud you for wading through this mess, trying to make sense of it, and actually responding to it. I wouldn't have bothered. One paragraph was enough to make my eyes bleed.

As for Fodor's proposal for evolution without natural selection, the byline on the review I saw said "Jerry Fodor is collaborating with Massimo Piattelli-Palamarini on a book about evolution without adaptation."

So there you go. Just wait for the book. I'm sure he spells the theory out in succinct, lucid prose.

Or you could do something more useful than reading his book, like jamming carrot peelers in your ears.

He discusses some philosophical issues concerning the proper definition of the notion of 'selection for,' but it looks to me like if you asked him where eyes come from, he would answer essentially like Richard Dawkins.

He'd answer that the Dawkins account can't tell us whether there has been selection for eyes or selection for vision or selection for organisms that see, and that this is somehow a huge problem, and then slither away before you could ask what his explanation for eyes is.

Seems to me Fodor has outlived his usefulness to the scientific community. Time was, he was a gadfly for cognitive revolution, keeping the big thinkers in check when they overstepped their bounds and made some outrageous claim. His early work on developmental constraints is well worth reading because it predicts many of cognitive pitfalls that have occurred, especially with his coining of modularity.

But he's become a bad parody of himself, and his little spats with Chomsky, Dennett and Pinker just seem tiresome and insubstantive. I don't even know what he's railing against anymore. Best I can figure, he's pissed that someone actually believed him when she suggested the mind might be highly modular. But while Chomsky and Dennett and Pinker have all taken those ideas and ran with them, Fodor seems stuck in the mindset that everything about the mind is too complicated to figure out, so why bother.

Have you ever stopped to think that yuor vertebrate eye example is a MACROevolutionary example? It is an amateur's cliché to think that you can point at it and say "selection for seeing explains this". I hope you may come to realize this by yourself cause I'm not motivated to explain myself much further on that point.

If we want to see as closely as possible how NS explains adaptation, we would want a field example, a relatively recent speciation or new phenotype, where directional selection has perfected a funtion by an accumulation of mutations; much like we can exaggerate a trait by artifical selection by accumulating several genes, we can hope to observe a similarly documented field example where directional selection is responsible for the origin of a new adpataion; note I'm talking of a simple adaptation: the length of a metatarsal, the size of the egg, etc.

Could you provide me an example of a field case of the origin of a simple adaptation by directional selection?

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

Fodor refers to the constraints of evolutionary history as "channeling." Is this common usage? I don't think I've ever heard it before, and the New Age usage of the word is off-putting.

By Tegumai Bopsul… (not verified) on 15 Oct 2007 #permalink

Ginger Yellow says:

"Everything I've read of Fodor's in the LRB in the last few years has come across as a bizarre, poorly argued dig at Dennett [...]."

Come now, he's made bizarre, poorly argued digs at plenty of people besides Dennett.

Vargas,

Out, damned troll!

Could you provide me an example of a field case of the origin of a simple adaptation by directional selection?

Sigh, not this nonsense again. Here are some, feel free to exclude the examples of wild-domesticated crosses if they do not meet your strict criteria:

Directional selection is the primary cause of phenotypic diversification

But you'll notice that Jason said several times that he is talking about complex adaptations. Obviously, the eye of any organism is and was not shaped by a single continuous bout of directional selection for "eyes".

Most of the time, selective advantage is more of a conseuence than the cause of the origin of an adaptation. Selective advantage can only be causal in the origin of an adaptation if it is the result of accumulation by directional selection.
Anyone fairly literate on the topic of the genetics of adpataion knows what I'm talking about here: adaptations that are an accumulation by selection of several genes with small effects.

Disclaimer: I am an atheist and a reseacher in evolutionary biology. Looming creationism forces some people to think we must commit to natural selection as the only true alternative to paley's argument for ID in complexity and adaptation. Amateur's stuff. Laughable.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

Windy, thanks. I was trying to remember which was that PNAS article I once read... and here you deliver it to me.it's great for chuckles. I remembered it because the gimnastics made to apply the selection tests are simply....unacceptable. Much like the cichlid paper you served me last time (and we can discuss that one as many times you want...I have happende to have found some other interesting literature about that...)

C'mon, Windy. Don't giv me this genralist crap papers "selection explaisn phnotypes". yeah, right. Give me just a humble field example, for a simple, measurable trait.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

Best I can figure, he's pissed that someone actually believed him when he suggested the mind might be highly modular.

Yes, it is bizarre to me that the once-champion of cognitive nativism is now railing against evolution. How else does one get nativism except by adaptation?

And my skin always crawls anytime I see the term "Darwinist" -- that's an indication to me that the writer has been reading too much ID material, especially when it is conflated with the meaningful term "adaptationist".

Alexander Vargas:

"simple, measurable trait."

You're asking for an example the origin of an adaptation by natural selection. But a simple trait might just require a single mutation, maybe just a duplication or even a point mutation (+ developmental accommodation to local environment), and hence is not an example of selection generating a trait. You're rigged the challenge by your "rules": you want an example of selection shaping an adaptation, yet you rule out complex traits.

This is an interesting development. Fodor has made a career of "fleshing out" Chomsky's ideas. He famously developed Chomsky's views on modularity, expanded Chomsky's ideas about innate concepts into the Language of Thought hypothesis, and now it seems he has tried to develop Chomsky's confused ramblings on evolution (Chomsky has always opposed the idea that language is an adaptation and has taken a few swipes at adaptation generally; of course it's difficult to know what Chomsky's views are exactly because his intellectual work is closer to a collection of statements than coherent arguments).

He has also been a rabid defender of Chomsky's "autonomy of psychology" thesis; the notion that psychology, cognitive science and linguistics are "autonomous" of biology. Chomsky did this by arguing that biology (indeed chemistry and physics) might/would/should adapt to psychology/linguistics and not vice versa. Fodor argued that "levels" of science needn't reduce at all (a position currently very popular in philosophy of science); so psychological explanations need not be consistent with biological explanations. It's interesting that his arguments here appear to rely on movement between the supposed "levels" of scientific explanation.

Thanks Jason. I got up early this morning to write a response to Fodor, but your excellent effort allows me to go fishing.

GH

By Gary Hurd (not verified) on 15 Oct 2007 #permalink

Why could not a simple, MEASURABLE adpataion be the result of several accumukated muataiosn? severla metric traits show variation caused by genes with small effect that can be accumuated by artificial selection. You talk as if reality is that "measurable" equals "single mutation" and thus I am asking for the impossible. I think it's hilarious you are accusing me of unfairness by demanding SIMPLE traits; if I demanded complex traits, it's just worse. You should know that.

In adpataions that have arisen by single muataions,a s seems to be dominatly the case in field examples, it is pretty clear that the selective advanatages are the consequence, and not the cause, of the origin of this trait.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

Alexander Vargas, in artificial selection there is a cessation of selection of all other traits other than the ones of interest to humans (fruit yield, plumage, coloration, temperament etc.), and plants and animals that would not be viable or successfully reproduce in the wild are cared for. The result of that is that there is greatly reduced selective trade-offs between beneficial traits. For example, between strength and speed, or plumage elaboration and predator evasion, or insect resistance and size of fruits. And so single-trait metric trends are far more rapid, unidirectional, uninterrupted by stasis and reversals, and uncomplicated by functional trade-offs than they would be under fluctuating wild conditions. So of course an example of your self-styled, highly limited criteria for adaptation via natural selection is far easier to find in artificial selection.

There you go. It is very difficult for selective conditions to give origin to an adaptation in nature. This can explain why we do not know any clear case where directional selection was causal in the origin of an adaptation

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

Alexander Vargas, a complex adaptation constructed on the phylogenetic substrate of accumulated past preadaptations is still an adaptation shaped by natural selection, however complex or macroevolutionary. Each stage in the lineage - the variant that gave rise to next stage - was determined by selection (and drift) determining the frequency of that variant. In fact, the more stages required for its construction (and so the more complex the adaptation), the more inescapable its determination by selection. Even if a given stage is designated a macromutation, or an exaptation, or selectively neutral, the sequence of stages (the connections of stages through morphospace that constructs the 'final' state of the complex adaptation) still has been navigated by selection affecting the frequency of (including eliminating) then-current variants.

"Even if a given stage is designated a macromutation, or an exaptation, or selectively neutral, the sequence of stages (the connections of stages through morphospace that constructs the 'final' state of the complex adaptation) still has been navigated by selection affecting the frequency of (including eliminating) then-current variants"

probably every step was something other than directional selection. Th fact the selection taht at every point selection is affecting reatiniance-elimination of a trait and its population frequency does not mena that selection is being directional, a causal guide of the evolutionary process. Therein is your mistaek; each step in the formation of the eye had selective conseuences, but selection was not causal or imparting direction; much less so in this deep time abstract sense that you are pushing yourself into.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

actually you argument mounts up to little more than saying "sequence of steps" = "selection" You might as well just say evolution=selection (many amateurs think this way) and point to the evolution of any organ as an example. Crap for amateurs.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

hmm oK I'll clean away the typos. I said:

Probably every step in the evolution of the eye was something else than directional selection. The fact that at every instant selection is affecting retainance-elimination of a trait and its population frequency, does not mean that selection is being directional, a causal guide of the evolutionary process. Therein is your mistake; each step in the formation of the eye had selective consequences, yes; but selection was not causal or imparting direction; much less so in this deep time abstract sense that you are pushing yourself into.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

You brought up the vertebrate eye, not me. Of course selection is shaping and maintaining the function of the eye. The sequence of stages was certainly not mainly constructed through drift, developmental constraint, molecular drive etc. Consider: what happens when selection for vision is relaxed?

It is amateurish to fail to recognize that if an alternative variant of a stage had higher frequency, then eyes never would have evolved or at least been been far different in structure and function. Your parlor trick of redefining adaptive traits as mainly single mutation variants and then denying that a sequence of functional stages through morphospace is due to the action of selection over generations is nonviable.

Whatever. The steps spread through time involved in the origin of the eye do not reflect the action of directional selection. If you are unwilling to understand this, suit yourself.
The eye is no good example for the action of natural selection; a field example for a measurable trait would be much better. But see, Colugo, you don't even care about th absence of true examples. Your ideology from empahsizing selection is pretty safe from any empirical discussion.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

"Of course selection is shaping and maintaining the function of the eye"

maintaining, yes. Shaping, no. But maintenance is not only dependent on selection.

"Consider: what happens when selection for vision is relaxed?"

The eyes may be lost. But this is not an example of how selection is supposed to generate adaptaion, isn't it. rather. It is a removal of a restriction. Everybody agrees that selection is a restriction. But this does not mena it is resposible for the origin of adpatations. I insist: selection is more of a consequence than a cause of he origin of adaptations.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

What is with your fixation with directional selection, Alexander Vargas? Anisogamy was, by necessity, produced by disruptive selection. And many complex adaptations are constructed though bricolage, hierarchies involving developmentally elaborated complexes of several simpler traits - which cannot be result of simple directional selection acting on a single metric trait.

"anisogamy was, by necessity, produced by disruptive selection"

"by necessity"? you mean you have no evidence for that. The fact is that what you say makes little sense. How could you have disruptive selection without some kind of pree-existing anisogamy? I see no evidence for selection "producing" anything here.

Selection of many different kinds is everywhere; but what we are discussing is how can selective advanatages actually be CAUSAL in the origin of adaptations; we are not discussing whether selection occurs, nor wheter it is only directional. etc. We are discussing its exact relationship to adaptation.

By Alexander Vargas (not verified) on 15 Oct 2007 #permalink

What a shame. The funny thing is, I was just recently introduced to a wonderful essay by Fodor on what's wrong with modern philosophy, but on first skim he seems to be falling into some of the silly linguistic ills he himself identified. Later I hope to read this carefully and try to figure out WTF happened.

He's made a career of ignoring biology, so should we be surprised that he is being sophomoric? This is the same guy who argued for decades that neuroscience is irrelevant for the study of mind.

He seems to have just caught up with some of the 'devo' half of the field of 'evo-devo'. Well, at least he is learning some biology.

My advice to any aspiring scientists: ignore the philosophers. If you have the urge to take a philosophy course, take a course in mathematics instead.

By Blue Devil Knight (not verified) on 15 Oct 2007 #permalink

Thanks for posting this, I was looking for someone to trash it because I could tell just from the technique that he was full of crap.

That and the basic failure to understand genetics. You briefly mention the foxes, but that was the clearest example of how Fodor just doesn't understand basic biology, in this case genetic linkage and also, I think, polygenic traits.

Fodor and Dennett have a history of tendentious disagreements. In one exchange

This is way more significant here than just some feud with Dennett ... did you actually read Dennett's response that lay's Fodor's absurdity bare? For instance

(III) There is no such thing as design without a mindful, intentional designer (fn 12).

Here Fodor sounds like Christoph Sch�nborn, Catholic archbishop of Vienna, the chap duped by
the Intelligent Design folks.

Based on this essay, I agree with Dennett's assessment.

Forget this essay, go back to the previous exchange and see how Fodor had already made a host of "assumptions" that are contrary to the real world and "Darwinism".

By truth machine (not verified) on 15 Oct 2007 #permalink

P.S.

Now this really is absurd. Silly absurd. Preposterous. It is conclusions like this, built upon such comically slender stilts, that give philosophy a bad name among many scientists.

It's bizarre that you didn't what it is that Dennett is saying is absurd and preposterous: "Contrary to Darwinism, natural selection can't change the distribution of phenotypic traits in biological populations".

And Dennett's summary of Fodor's argument, which Dennett finds valid, is

either you go
Dennett�s way, or you must conclude that evolutionary biology is one big mistake.

Fodor rejected the former and embraced the latter. Dennett of course went the other way.

By truth machine (not verified) on 15 Oct 2007 #permalink

He'd answer that the Dawkins account can't tell us whether there has been selection for eyes or selection for vision or selection for organisms that see, and that this is somehow a huge problem,

Dennett describes this sort of thing more generally in the "tendentious disagreement" (would one say that of an evolutionist's disagreement with Behe or Dembski?):

And note that Fodor needs this license to dichotomize for his argument. He loves to
construct fish-or-cut-bait dilemmas in his arguments--look at steps (iii) and (iv), the latest
examples in a long line of such arguments going back at least to The Language of Thought
(1975). You simply can�t run such arguments without the hard edges of essentialism at your
disposal, and when things look ominously fuzzy in the middle ground, threatening to mess up the
nice forking path Fodor is preparing, his typical tactic is make a little joke and simply insist on
it. (Packing this move off into a footnote discourages people from demanding a review.)

By truth machine (not verified) on 15 Oct 2007 #permalink

Fodor has a big issue with Evo Psych, for years he's been ranting against the work of Cosmides and Tooby, most of it well off target. So I'm not surprised this piece was all set up to have another dig.

There are some good criticisms of this area of psychology, like that of Panksepp (e.g., must be neuro-based). And to some extent they are overcoming this issue with lesion and fMRI studies.

By melatonin (not verified) on 16 Oct 2007 #permalink

To the question on channeling, it is a vaid term created (I think) by C H Waddington.

I love the comments in this essay where Fodor hints that he is privy to secret research that will rock the foundations of biology. His lab must be next to Dembski's in the DI Fortress of Solitude on Volcano Island.

I think Fodor is arguing that the mind/conciousness/whatever is a spandrel, an accidental necessity of developing a brain adapted to a certain seqence of environments and ecologies. Assigning meaning to our minds is like painting the spandrels of a church, after all "a spandrel is a terrible thing to waste". Explaining the utility of envy is pure adaptationist spandrel painting in his view.

By David vun Kannon (not verified) on 16 Oct 2007 #permalink

Did you hear about the early Jurassic philosopher who claimed that that absence of wings on dinosaurs was a major obstacle to any theory of natural selection and adaptation?

Vargas, everyone knows that the mutation has to come first before it can spread in a population.

You will not get examples of selection being the cause of the mutation.

By Pete Dunkelberg (not verified) on 16 Oct 2007 #permalink

Pete, do you seriously mean to tell me, that no one has ever seriously maintained that selection has a causal role in the origin of adaptations? Isn't selection supposed to give rise to new adaptations through a directional accumulational of mutations? What card are you trying to play here?

By Alexander Vargas (not verified) on 16 Oct 2007 #permalink

we are not talking about the origin of mutations, we are talking about the origin of adaptations.

By Alexander Vargas (not verified) on 16 Oct 2007 #permalink

To add wings to a pig, you'd also have to tinker with lots of other things. In fact, you'd have to rebuild the pig whole hog: less weight, appropriate musculature, an appropriate metabolism, an apparatus for navigating in three dimensions, a streamlined silhouette and god only knows what else; not to mention feathers. The moral is that if you want them to have wings, you will have to redesign pigs radically.

Indeed, quite correct. And, it's been done--bats. In order to "redesign pigs radically," the redesign had to begin very early, at the time of the last common ancestor of what we now call "pigs" and "bats." The way Fodor put it was along the lines of "Ya never seen a dog give birth to a cat."

Darn you, Mark! I was going to mention bats.

Think I will anyway. While I don't really understand where Fodor's going with his non-existent flying pig -- actually, strike everything from 'with' onwards -- it seems to me a rather dangerous quadruped under which to shelter.

If you ask an evolutionary biologist the question "Why aren't there flying pigs", you'll get a variety of answers depending on what aspect of the absence you care about most. (It's actually a pretty good style of question: "Why aren't there ants as big as pigs?" or "What happened to the giant dragonflies of the Carboniferous?" are great hooks for all sorts of interesting essays.) And if you ask the same EB "Could there be flying pigs, and if so how?", you'll get a lesson in how bats actually evolved - and the sort of things that would have to happen for a distant pig descendant to take to the air as something other a British Airways breakfast sausage.

But ask any of the questions above of someone who doesn't hold with mainstream evolution, and you won't get an answer worth one of the above sausages. You won't be able to take any part of that answer and use it for anything other than parrotry on teh intarwebs. You won't even be propelled into an intriguing thought experiment that goes 'if that... then this', of the sort that lets the improbability of the 'if that...' go by the board because the 'then this...' illustrates something new and interesting.

It used to be that the implacable opposition of creationism to rationality in word and deed got my goat the worst. Now it's just the sterility, the utter lack of utility, that annoys me the most. It's good to change one's motives from time to time, especially when the source material is so incapable of coming up with one darn new idea that doesn't stink.

Isn't selection supposed to give rise to new adaptations through a directional accumulational of mutations?

The only "direction" of the accumulation of mutations is toward fitness, which varies over time as the environment changes.

I insist: selection is more of a consequence than a cause of he origin of adaptations.

You can insist whatever you want, but it just makes you look pig-ignorant and dimwitted.

By truth machine (not verified) on 16 Oct 2007 #permalink

Hmm. It looks to me as if Fodor's opposition to NS is because it's not predictive in the long run - you can only predict, with NS, what will happen until the next mutation or environmental change.

IOW: It can make negative predictions, but never (interesting) positive ones of the sort "this will happen".

(Which it can't. But then, it seems incredibly unlikely that anyone will ever come up with a theory that'll provide useful predicting on that topic, because it's so very stochastic.)

By Michael Ralston (not verified) on 16 Oct 2007 #permalink

it is pretty clear that the selective advanatages are the consequence, and not the cause, of the origin of this trait.

This is a linguistic and conceptual muddle. selective advantages of what? A trait may result in a fitness advantage: organisms carrying the trait are more likely to survive. But selective advantage is a property of the trait and its causes, not the organism. Fit organisms survive, traits are selected, fit organisms survive, traits are selected, ...

By truth machine (not verified) on 16 Oct 2007 #permalink

It looks to me as if Fodor's opposition to NS is because it's not predictive in the long run - you can only predict, with NS, what will happen until the next mutation or environmental change.

So Fodor rejects NS because it can't predict when the next meteor will hit the Earth.

By truth machine (not verified) on 16 Oct 2007 #permalink

Your parlor trick of redefining adaptive traits as mainly single mutation variants and then denying that a sequence of functional stages through morphospace is due to the action of selection over generations is nonviable.

Well, it's "viable" in the sense that it keeps his trollery alive. It gives him a handle for pestering scientists with "Your science can't work! Show me how your science can work!" What does he and his ilk really think will come of this? Aside from stasis, the only possible outcome is for them to realize they're in error, but as their behavior is driven by a determination to show that "the establishment" is wrong, they are highly resistant to that.

By truth machine (not verified) on 16 Oct 2007 #permalink

Looming creationism forces some people to think we must commit to natural selection as the only true alternative to paley's argument for ID in complexity and adaptation.

Nice ad hominem you've got there, Vargas, but no,

By truth machine (not verified) on 16 Oct 2007 #permalink

I'm not motivated to explain myself much further on that point.

If only.

By truth machine (not verified) on 16 Oct 2007 #permalink

pigs lack wings because there's no place on pigs to put them.

The contrapositive of this statement (which is logically equivalent to it) is: If there were a place on pigs to put wings, they would have them.

Fodor is a fool, or expects his readers to be.

By truth machine (not verified) on 16 Oct 2007 #permalink

Don't panic, truth machine. Calm down.
You won't need to run to a church if you are a non-selectionist, I assure you. It's perfectly OK to be non-selectionist. D'Arcy Thompson was. Bateson was. Goldschmidt was. Plus I am not predicting any revolution nor the end of darwinism nor anything like that. We have heard that one for a long time.

I think it is pretty easy to imagine how selection can be causal in directing the origin of an adaptation. Do you disagree with this "wording"?

By Alexander Vargas (not verified) on 16 Oct 2007 #permalink

"...Natural selection is a process that affects gene frequencies in populations of animals over many generations.."

Who and when was this established in what journal, page number ?

TongueSpeaker:

Fisher, R. A. 1930. The Genetical Theory of Natural Selection. Clarendon Press, Oxford. pp. 1-265.

Therein is your mistaek; each step in the formation of the eye had selective conseuences, but selection was not causal or imparting direction...

Right, so the reason you don't happen to have extra penises or dummy bumblebees hanging from your face in place of eyes is that mutations, not selection, have fortuitously been driving the evolutionary process towards eyes? Color me unconvinced.

Vargas wrote:

selective advantage is more of a conseuence than the cause of the origin of an adaptation.

and

we are not talking about the origin of mutations, we are talking about the origin of adaptations

Apparently everyone here recognizes this is nonsense except Vargas.

1. The first quote is a truism, the proper response to which is, "duh." The origin of an adaptation is a random mutation, which obviously cannot be caused by its advantage, which can only come after the existence of the mutation. To use this as an argument against adaptation is in fact to support an adaptationist argument.

2. The second quote is meaningless wordplay. All adaptations originate in a random mutation, otherwise there would be nothing new for natural selection to work on. To posit any other "origin" for an adaptation is nothing more than a pretence at deep insight.

For the record, where do you do your biological research? Your trying to depict yourself as an expert, so tell us. What are your qualifications? Please list the peer-reviewed publications in which you've undermined the adaptationist method.

Thanks, James Hanley. But it will do no good. Vargas (aka Sanders) knows better than anyone else; those who dare argue with him are "amateurs" (spelled variously) or "retards." He will never say what he believes to be true in any clear fashion, being content to tell other people they are wrong without elaboration. I gave up trying to talk sense to the guy over at Sandwalk (though windy still gives it an occasional go, to no avail).
My feeling is that Vargas does not understand the concept of a "population." I also suspect that he does not get the difference between "adaptation" in the evolutionary sense and in the physiological sense.
Maybe somebody with more patience than me could ask him some time what the hell "epigenetic adaptation" is supposed to mean.

By Sven DiMilo (not verified) on 17 Oct 2007 #permalink

Not to mention that the Vargas-inspired discussion on whether mutations are generally of large or small effect has nothing to do with Fodor's silly semantic argument against natural selection. Whereas Vargas would accept the role of selection in, say, industrial melanism in the peppered moth, but argue for a determining role of the original mutation in the process, Fodor would get stuck chasing his own tail on whether the selection benefited black moths or moths that matched their environment!

I think it is pretty silly to think that becuase we can define evolution as change in the gentic composition of populations, we esign form discussing the evolution of actual trits. maybe to an amaetur, it is fine to leave organismic change out of the pivture and content himself with tgene frequencies. But to people who like me are genuinely interested in biology, this is just silly. We MUST discuss traits and organic change. It is not enough to point otu that selection can change population frequencies.

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

"Right, so the reason you don't happen to have extra penises or dummy bumblebees hanging from your face in place of eyes is that mutations, not selection, have fortuitously been driving the evolutionary process towards eyes? Color me unconvinced"

Are you being serious? Talk about amateurish arguments...
The fact you do not have penises instead of eyes, is not evidence that natural selection guided the evolution of your eyes.
Negative selection ALWAYS eliminates malfunctional mutations, even if we are in stasis. It is insufficient to direct the origin of new adaptations, even if it DOES restrict some possibilities. As all should know (except amateurs), the actual path taken by evolution is also a matter of the actual mutaion coming about, that is, what development can
actually come up with.

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

Genes with small effects are everywhere; this is what makes me confident that I am not asking for the impossible if I ask for a field example of an adaptation that is the result of selective accumulation of such genes.

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

James Hanley, you need to read more, or leave the people who know what they are talking about alone.
Selection CAN be causal in the origin of an adaptation, if it produces a directional accumulation of SEVERAL genes, that originates an adaptaion. The idea is that without this DIRECTIONAL selection, such accumulation would not have occurred and we would have no new adaptation.

Now, when adaptations are the result of a single muation, you are right. Selection is not causal. Selection can only be causal in the sense of producing a directional accumulation of SEVERAL mutations.

Think about it.

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

I think its funny when narrow-minded zealots accuse intellectual giants of not understanding their cherished theories when the smell of criticism wafts in their direction.

"The crucial test is whether one's pet theory can distinguish between selection for trait A and selection for trait B when A and B are coextensive: were polar bears selected for being white or for matching their environment? Search me; and search any kind of adaptationism I've heard of. Nor am I holding my breath till one comes along."

Does this mean something? Aren't white and matching the environment the same thing? Or is this just an extension of my lifelong inability to find meaning of any kind in philosophy?

Alexander Vargas:

Are you part of a larger anti-selectionist school of thought besides the long-dead mutationists you cited? Or are you a "school" of one? Because if so, and if you're right, you must be one of the most important evolutionary theorists to come along in decades. Of course, it is more likely the case that you are wrong.

I am just another non-selectionist. We come in different flavors. And I don't think we have ever ceased to exist, here and there. Mutationism, for one, is not dead, you should know that. Have you verer heard about "antiadaptationism" ? Complaint against excessive emphasis on natural selection.

There is no such thing as total agreement with what I think and ANY "school". I think everybody must makes his own mind or shut up.

You may think that unless it is majority, a permanent minority is more likely to be wrong. These are vague indications indeed to decide whether to be a selectionist or not. More like the flailing swoops of a blind man's stick, if you ask me. As I said, everyone should make up his own mind.

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

Please define evolution? The term has been used so carelessly that a conventional definition seems to be difficult to pin down. In any discussion, it would be helpful to precisely identify what the theory is before discussion ensues.

We have the human genome and the chimp genome, and no indication that any macromutation is responsible for the difference between us.

By Pete Dunkelberg (not verified) on 17 Oct 2007 #permalink

Pete, exactly what kind of indication would you expect? It's not easy to observe the function of the chimp version of a gene in humans or vice-versa, you know. Most of studies that can measure the effects of genes are carried out between species diverged recently enough that hybrids are still possible. For comparing chimps and humans, experiments in cell cultures is probably the *best* we can do right now...

By Alexander Vargas (not verified) on 17 Oct 2007 #permalink

Alexander,
Are you saying that limitations in technology prevent us from being able to carry out any meaningful test of the theory?

no. dummy.

By Alexander Vargas (not verified) on 18 Oct 2007 #permalink

Cole, read Lewontin's criticism of the definition of evolution of dobzhansky ("change in the genetic compsotion of poulations") in "The genetic basis of evolutionary change" (1974)

"A description and explanation of genetic change in populations is a description and explanation of evolutionary change only insofar as we can link those changes to the manifest diversity of organisms in space and time"

By Alexander Vargas (not verified) on 18 Oct 2007 #permalink

Perhaps we can step back from the bickering of mini-arguments and try to figure out what we are actually saying to find a common ground, or at least main principles on which we disagree--or maybe that's not how its done on blogs, I'm kind of new to this.

It may be that what is really dividing us is our personal and unspoken definitions of causality.

Let me try to make a statement most everyone could agree with: Mutations (of many kinds) cause variations (of many kinds) in the traits of individual organisms (though these variations are constrained by the genetics of the currently existing organism)--these organisms with slightly different traits may either live and breed or not live and breed, leading to either the end of those traits/genes or the increase in the proportion of those traits/genes in the population.

"Selectionist" people seem to take the mutations for granted and focus on the changes that occur after variant traits have arisen in individuals (ie. natural selection--the second half of the statement above). This seems to be done because the mutation process is considered a relatively random one and in some definitions or interpretations of causation, a random process is not satisfactory to explain the distinctly non-random outcome (ie. white polar bears rather than blue or black or yellow ones).

To be generous to Vargas, let me suggest what you might be thinking. You might think the statement I wrote above is generally true, but think that since mutations are absolutely necessary for the process, and that they are temporally before the positive, negative, or neutral selection process (which does not actually generate the traits themselves, but can only fix or remove existing traits), that mutations should be considered the "cause" of new traits.

So both parts of the whole can claim to be the "cause" of the changes in evolution, and you can argue about how each occurs and which one is more important, but both halves are necessary for evolution, and if you spend your time denying the role of the other half, then you are simply confusing and aggravating rather than having any sort of real discussion.

If any party feels I have misinterpreted, please do not insult me or my mother or my scientific abilities, but clarify what you think is actually responsible for the evolution of differences in organisms, since obviously I missed it.

You don't have to believe every "just-so-story" written in selectionist language if you think natural selection is involved in evolution, and you don't have to reject natural selection completely if you think that some of the "just-so-stories" are untestable hypotheses that reach a bit too far.

I think it's interesting that in many conversations of this sort, the guy calling everyone "amateur," who also has a revolutionary argument that nobody seems to get, also needs a spell checker. How hard is it to fix the errors, and make the reading of the posts easier on everyone else?

I notice this in evolution/creation debates. Creationists often have spelling issues. It's true! And funny actually.

Not to mention the convenient ignoring of specific questions regarding his/her training, pubs, and area of research. Pretty classic troll.

And how hard is it to give an example of the type of "field experiment" you are asking for? Explain yourself man.

On second thought, never mind. haha.

Hi there,
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Jesse, thank you. I will not watch your videos. I stopt being religious and believing in God, when I grew into puberty. And that's a long time ago.
I feel very sorry for Professor Fodor, who obviously don't know much about biology, and advise him to take up another subject, like behaviourism maybe?

Jesse, I watched your videos and now I believe in God! Thanks.

I never knew it could be so easy.

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Given Fodor's rather opaque language it is no surprise he miscontrues the meaning of some terms. The term Natural Selection was really Darwin's convenient term to draw analogies to artificial selection, a concept that was well understood in his time. The confusion is that in the common venacular, selection implies intent or premeditation, both of which natural selection lacks and which Darwin made a great effort to explain. Fodor refers to natural selection as a mechanism. It is not. Genetic heredity is the mechanism and natural selection is a process driven by that mechanism.

It should surprise no one that we have built on Darwin's foundation and added nuance to our understanding of evolution. What is surprising and makes Darwin's idea so powerful is that the fundamental truth of the idea has held up against relentless examination. Natural selection may not be the only process of evolution, but it clearly is the dominant process of evolution.

By Chris Jones (not verified) on 29 Apr 2008 #permalink

Notice that I am not saying anything incompatible with the extensive amount of selection studies. Selection occurs. But how much does it really explain?
For instance, in Dawkin's mind, it is possible to use the evolution of the vertebrate eye as an example of the action of natural selection. The implication of this is that the CENTRAL mechanism involved in the evolution of the eye is natural selection. "Selection for seeing" shaped the evolution of the eye. Is this the truth? Or has Dawkins reached beyond what natural selection truly explains?

Similarly it seems just a matter of pointing your finger at the human brain or mammalian middle ear and say "selection for thinking" and "selection for hearing".

My protest is a paleobiologist's protest. Read "full of hot air" in Gould's "eight little piggies". Redundancy and exaptation is key to understand how big functional changes were made possible, with transitional forms remaining adaptive. In fact darwin himself realized this, even though he did not make it a prominent part of his theory (favoring natural selection instead)

In words of Gould:

"But rules of structure, deeper than natural selection itself, guarantee that complex features must bristle with multiple possibilities- and evolution wins its required flexibility thanks to messiness, redundancy, and lack of perfect fit"

Gould provides a couple of pretty clear examples of what he's talking about: the mammalian middle ear, and the evolution of lungs and air bladders of tetrapods and teleosts. And I happen to think, it's important to get your boots muddied and go from the theory to real cases. This is no string theory (though I'm sure some non-very-biological "evolutionary experts" think it is). Organism are quite tangible, and so are their fossils. A little BIOLOGY and NATURAL HISTORY are available to understand things.

It's a truism that all changes along the evolution of the vertebrate eye were favored or at the very least admitted by selective conditions. But thinking about population genetics has little to offer as to explaining how did we go from breathing water to air, or how did bones at the hinge of jaw and skull ended in the middle ear of mammals. These questions have an answer in organismic and biological terms, and an empirically documented evolutionary history that can often be amazingly detailed (such is the case in the mammalian middle ear)

Anyone that has really studied the evolution of a complex adaptation will find spandrels and exaptation to be crucial. bacterial flagellum, vertebrate eye, you name it. I think any description of the evolution of a REAL complex organ that excludes exaptation is utterly incomplete, and an omission that is too gross for me to consider natural selection alone to explain complex adaptation. Selection is crucial, that is, it is necessary to understand the evolution of the eye: But it is not sufficient. The same thing can be said about exaptation.

By Alexander Vargas (not verified) on 28 May 2008 #permalink

After quoting Fodor, Les asks:

'The crucial test is whether one's pet theory can distinguish between selection for trait A and selection for trait B when A and B are coextensive: were polar bears selected for being white or for matching their environment? Search me; and search any kind of adaptationism I've heard of. Nor am I holding my breath till one comes along.'

Does this mean something? Aren't white and matching the environment the same thing? Or is this just an extension of my lifelong inability to find meaning of any kind in philosophy?"

If Les has trouble withdrawing meaning from this sort of philosophy, he should turn to mathematics, where the idea of "coextensiveness" was introduced by Gottlob Frege. Basically (though with a different example), Frege made the following point: Superman is Clark Kent, but just because the expressions 'Superman' and 'Clark Kent' are coextensive (i.e. they refer to "the same thing" as Les puts it), that doesn't mean that they have the same meaning -- after all, Lois Lane would agree that it's true that 'Superman is cute' but not that 'Clark Kent is cute'. So that's co-extensiveness in a nutshell. Even though 'being white' and 'matching the arctic environment' are coextensive, they don't have the same meaning. It's not all that hard; it's from math.

As for Fodor, he got into this argument by going around the barn over and over again with Dennett et al. about evolutionary psychology. The frequent refrain from that camp would go: how do we explain psychological states? well, as products of natural selection. And Fodor's recurring retort was: who's doing the selecting? Clearly, "mother nature" isn't, because she's just a metaphor. And since there doesn't seem to be anyone else literally selecting one trait over another, there can't be any real *selection* going on in the first place. Indeed, within the context of psychology, the whole argument is viciously circular since it has to appeal to the *intentions* of an anthropomorphized entity like mother nature in order to explain psychology, which includes, among other things, intentions.

Fodor's point seems completely valid to me. In the future, we'll look back on Darwin's theory and appreciate the analogy between breeding and "natural selection" as a helpful, but limited analogy for understanding evolution. But knowing what we now know about the mechanism of evolutionary change (which Darwin didn't), we can appreciate the limits of this metaphor. And so science progresses.

F has just published a book with Piattelli-Palmarini expanding his points. F&PPs are wrong about much if not most of the petty details that their book included about natural selection (NS) and evolution by natural selection (EBNS) as well as about what students of NS and EBNS can and cannot disentangle; but they got the most important thing right:

Game-theory(GT)-based narratives about nature (e.g., evolutionary-biology narratives invoking the principle of NS and its obvious implications for the evolution and the diversity of the living) are exercises in math rather than âscientific theoriesâ if their legitimacy derives only from their being backed by proper GTal analysis and assumptions. Sex-ratio theory is an example (see below).

Such narratives cannot be compared to a true scientific theory like that of gravitation unless they appeal to unifiable natural-historical facts, entities, and processes.

NS narratives fall between these two extremes because they mobilize a firework of circumstantial and non-unifiable natural-historical details that are GTally relevant (in ceteris-paribus or dynamically positive ways), and yet at least abstractly speaking they assume, almost always implicitly, a unifiable background âforce fieldâ.

Indeed in any NS event the âwinnersâ are always âthe resultâ of the Bauplanâs cybernetic potential to be altered (due to mutation, etc) so that modified âunitsâ can show up that deal with the specific selective agent/regime better than other co-occurring units do.

This *non-exhausted* cybernetic potential is also a big part of the unifying âgravity-likeâ force driving EBNS and is part of what Van Valen went after when he proposed what he called âthe 3rd law of natural selectionâ (1976; he meant EBNS when writing ânatural selectionâ).

Current GT-oriented evol.bio models have nothing âontologicallyâ comparable to offer (i.e., they have no obligate links to the ultimate unifying natural entities and quantities that cause NS and EBNS âforce fieldsâ).

These stories are indeed âdifferent for each caseâ (letâs celebrate diversity!) because they are ontologically truncated and --to this extent and so many years after darwin-- they make a mockery of science: Imagine people discussing cases of selection imposed by a predator and hearing them talk non-stop about faster muscle fibers, better camouflage, favorable shifts in activity pattern, better olfactory detection of the predator, etc, i.e., a litany of sufficient but *not* necessary things under selection, but never witnessing anybody mention the necessary thing which is âto avoid being killed by the predatorâ (but note that a narrative that stops at the latter statement would still be âontologically truncatedâ because it would not apply to all living systems!).

Like many others before, F&PP had the gut feeling that the unifying âgravity-likeâ forces driving NS and EBNS are unknown and neglected. Indeed, in the recent bloggingheads exchange between Fodor and Sober ( http://bloggingheads.tv/diavlogs/26848 ), Sober won every exchange but was strangely silent when towards the end Fodor lambasted NS-based narratives as tirades listing âone damned thing after anotherâ.

Ironically, Sober in his masterpiece, The Nature of Selection (1984; in which Lewontinâs greasy fingers left marks in every other page), tried to canonize such explanatory âdiversityâ by positing the âsupervenienceâ of fitness with respect to its material causation (two individuals may have the same fitness even if one is say a bird and the other a bacterium, which âimpliesâ that *obviously* the material causation of the two fitnesses cannot possibly be compared let alone be considered for unification).

Any serious scientist would cringe at this schizophrenic claim for epistemologico-ontological âsingularityâ for evolutionary-biology narratives, and with good reason: The world is only one and natural phenomenologies that are not unifiable are best studied by French charlatans [already seen Leotard's idiocies about life, evolution, and "la condition humaine" ? ;) ]

Van Valen with his â3rd law of natural selectionâ and several authors with earlier efforts never considered elevating such transient helplessness and ignorance to an intrinsic âalmost-meritâ of evolutionary-biology narratives.

Take a look at vVâs paper (cit. below) and ask yourself if the âidiot-savantsâ F&PP (boy if they say stupid things otherwise!) would be able to disparage vVâs effort as one more instance of an ad-hoc narrative full of âone damned thing after anotherâ (even if the law were wrong).

Imagine if modern physicists were still stuck describing free and not-so-free falls, of various bodies of disparate nature in the most various media, of varying spatio-temporal heterogeneity, etc, etc, and telling us that they need to "study" even more such cases and hopefully to âfind the atomsâ in order to make âeven more sense!â of the âholy fact of free fallâ discovered by the ancient Newton!

Yes, in his tired recent NYRB piece on this affair, Lewontin mentions that F&PP stated somewhere that they are not asking for such a unifying force, but the real question is whether they would have anything to grumble about if the unifying force was already a central focus of research in evol.bio.

All in all, the trailer-park-level understanding of what a scientific theory should be that has been put on display by too many phil.of biol and evol.biol establishment frauds who have been falling upon each other to denounce apoplectically the many moronic errors in the âidiot-savantâ book by F&PP rivals not necessarily favorably with that of the peddler of puerilo-retarded animistico-suggestive anthropomorphizations, r.dawkins (written small), and their arguments are barely less misguided and heuristically less pernicious than dâs trademark syllogistic imbecility about âDNA with intentionalityâ.

Truly, itâs shocking to see --among âprofessionalâ philosophers of science-- such ignorance of the deep epistemological canons that distinguish better-developed/-grounded scientific theories, and to see --among âprofessionalâ evolutionary biologists-- such ignorance of deep evolutionary biology.

This whole debate shows one more time what kind of dysfunctional charade the american system of promotion of self-complacent paper-churner/grant-chaser/university-bureaucrat-pleasing hybrid frauds has generatedâ¦

[ Leigh Van Valen: ENERGY AND EVOLUTION; Evol. Theory 1: 179-229 (April, 1976) and citations therein]