ONLINE MARCH 17, 2010
“Misunderstanding Darwin”:
“Misunderstanding Darwin”:
An Exchange
Read Ned Block and Philip Kitcher’s review of What Darwin Got Wrong, by Jerry Fodor and Massimo Piattelli-Palmarini.
See Block and Kitcher’s rejoinder to Fodor and Piattelli-Palmarini, below.
Jerry Fodor and Massimo Piattelli-Palmarini:
When we were writing our book, it occurred to us that there was a kind of misinterpretation of which a very incautious reader might be guilty, and which we ought to do our very best to block. We did do our very best; but to no avail. Ned Block and Philip Kitcher make precisely the mistake that we’d dreaded. Worse, they then proceed to commit several other misreadings, the possibility of which, we admit, had not occurred to us. We’ll now do our very best to correct their mistakes, but time and space are pressing, and the opportunities for misinterpretation are, it appears, boundless.
First misreading: Block and Kitcher think we argue, erroneously, that “with respect to correlated traits in organisms—traits that come packaged together—there is no fact of the matter about which of the correlated traits causes increased reproductive success.” They then speculate that we are making “the very ambitious claim that whenever there are correlated traits there is no fact of the matter about which of the traits causes any effect.”
But, of course, we don’t believe, still less endorse, either of these theses. In fact, we think both are preposterous. We therefore spent our whole seventh chapter discussing a number of ways in which the causal roles of confounded variables can be, and routinely are, successfully distinguished. There are many such, the most obvious of which is perhaps John Stuart Mill’s “method of differences.” In effect, you run an experiment in which one but not the other of the correlated variables is suppressed. If you still get the effect, then it must be the variable you didn’t suppress that’s doing the causing. (If you think it’s maybe the ice rather than the alcohol that makes you tipsy, try taking one or other out, drink what’s left, and see what happens). People, scientists very definitely included, do this sort of experiment all the time. And often it works fine; we report lots of cases in our book. All this is familiar from Philosophy 101; do Block and Kitcher really believe that, old and case-hardened as we are, we could have failed to notice this?
However, the questions of whether there is a fact of the matter about which variable causes what, and whether this fact of the matter is epistemically accessible, really must not be confused with the question of whether natural selection, as neo-Darwinians understand it, is able to distinguish the causes of fitness from their local confounds. You and I can work out what caused what in all sorts of ways: we can use Mill’s method, or we can take the system of causes and effects apart and find out what mechanisms operate inside it, or we can ask the guy who built the thing (if somebody did) how it works, or we can look it up in the scientific journals, or we can ask Google, and so on and on. But natural selection can’t do any of these things. It can’t look inside, and it can’t run experiments, and it can’t contrive theories about internal structure, and it can’t consult the intentions of the builder. Doing any of those requires having a mind, and, by general consensus, natural selection doesn’t have one. All natural selection can do is respond to correlations between phenotypic traits and fitness. And that doesn’t help because, by assumption, if either of the confounded traits is correlated with fitness, so too is the other.
(We think, by the way, that it’s no accident that the notion of selection Darwinians favor is so thin. What they want is a theory of evolution that applies to any creature in any ecology. We doubt that such a theory is possible. We think that how a creature’s trait evolved in its ecology is likely to be very sensitive to which creature it is, and which trait it is, and which ecology it is. Such facts belong to natural history which, like historical explanations in general, reveals the causal antecedents of phenomena, not the empirical necessities that subsume it. That, however, is another story; one that we try to tell a little in our book).
Darwin needs an account of selection-for that distinguishes phenotypic traits that cause fitness from traits that are merely correlated with traits that cause fitness.
Second misreading: The last part of Block and Kitcher’s review offers an account of the opacity (or otherwise) of “cause.” It’s not an account that we favor, since we think it’s most implausible that causation is a relation between properties: causes and effects have dates and times, but properties do not. (Roughly, we think causes and effects are events which consist of the instantiation of properties. Properties don’t cause anything, though their instantiation often does. The reader, however, may feel that only a philosopher could care, and we suspect is right to feel that.)
Anyhow, it simply doesn’t matter to the present issues. What matters here is that, by stipulation, selection-for is sensitive to distinctions among locally coextensive states; i.e., it can distinguish between A’s causing Cs and B’s causing Cs even when every actual instance of an A is accompanied by an actual instance of a B and vice versa. Darwin’s theory of natural selection just is that phenotypic traits are selected for their effects on fitness. So Darwin needs an account of selection-for that distinguishes phenotypic traits that cause fitness from traits that are merely correlated with traits that cause fitness. Just as Block and Kitcher say, natural selection “make[s] a causal claim: having the trait causes greater reproductive success.” That being the claim, Darwin is in need of a mechanism that responds differently to A-caused Cs on the one hand and to B-caused Cs on the other, and that does so with no access to the endogenous structures of organisms; indeed a device that responds selectively to A-caused Cs and B-caused Cs even though it has access to nothing at all except correlations between phenotypic traits and fitness.
We don’t think that there is or could be such a mechanism. We have heard of many ways of distinguishing confounded variables, and none of them will do the job. In any case, this line of argument has precisely nothing to do with our (and Darwin’s) occasional indulgence in heuristic personification; and precisely nothing to do with “the
thesis . . . that natural selection can make the same finely graded discriminations available to a human (or divine?) observer.” Where on earth did that come from?
We think what’s emerging is a quite deep disagreement over what the theory of natural selection is supposed to be and do. Our view on this agrees with what practically every Darwinist we’ve come across has claimed: natural selection is supposed to be a theory of adaptation; i.e., it’s supposed to explain how adaptive phenotypic changes become diffused in a population; i.e. it’s supposed to explain what instances of adaptation have in common as such. This is the traditional, mainline, view of what theories are for (Plato: a theory of beds would explain what beds have in common as such; Saul Kripke: science discovers essences; etc.) A mere chronicle of instances of adaptation would not therefore amount to a theory of adaptation. It would just be “natural history.” We haven’t the slightest doubt that Darwin thought that he had discovered a theory of adaptation. It was, to be sure, a pretty thin theory, as it would have to be in order to apply to evolving creatures as such, whatever their phenotypes and whatever their ecologies. But it’s quite thick enough to be substantive; indeed, it’s quite thick enough to be false.
The outlines are familiar:
• There is random variation of phenotypic traits.
• There is some ecological variable that is sensitive to the strength of the correlation of such traits with fitness.
• There is some mechanism that alters the relative frequency of the trait in the population so that, all else equal, it varies with the strength of the correlation between the trait and fitness.
For example, suppose random variation produces a trait that tends to make its bearers invisible to their predators. Then, all else equal, the predators gobble up the creatures that don’t have it, and the relative frequency of the trait in the population increases from generation to generation. To repeat, we haven’t the slightest doubt that this is the process that Darwin called natural selection and that Darwinists have always believed in some or other version. In fact, it sounds pretty good. It sounds like it ought to work.
But it doesn’t. A way to see that it doesn’t (not by any means the only way) is to consider confounded (linked) phenotypic traits, one but not the other of which is fitness-enhancing. Both traits are then correlated with fitness, so both should count as adaptations according to the formulation of natural selection given above. But only one of them is a cause of selection, so only one of them is an adaptation, and, though both are selected, only one is selected-for. Thus the free-rider problem. Prima facie, free riding is a counterexample to natural selection.
As far as we can see this objection to natural selection is decisive. If so, there are two ways in which the dialectic can now proceed. First, one might try for some alternative to natural selection, one that doesn’t have a free-rider problem. We think there is unlikely to be such an alternative simply because there is no inference from correlation to causation, and, by definition, it’s the latter, not the former, that natural selection requires of the traits it selects for. The other possibility is to give up on the project of finding a mechanism for evolution and study the fixation of adaptive traits case by case. Since all the evidence suggests that they are extremely heterogeneous, this should keep evolutionary biologists busy well into the indefinite future. It is what we think evolutionary biologists actually do for a living (despite their inaccurate claim to believe in the theory of natural selection.) We hope not to sound petulant, but the last couple of chapters of our book go on about all this at considerable length. We do hope you will have a look at them.
One final point. Block and Kitcher keep suggesting that we don’t know enough about biology to criticize a theory that so many biologists hold dear. We are unmoved. For one thing, there is, as far as we can tell, much less consensus among experts than Block and Kitcher suggest. Certified evolutionary biologists have aired their disagreements in many publications over the years. Some are unwavering in their allegiance to the “modern synthesis” (the fusion of Darwinism with genetics); some advocate revisions and extensions, even radical revisions and radical extensions; and some have declared that the modern synthesis is dead. Quite likely, the neo-Darwinists constitute a majority. But so what? Surely, it’s common ground that the truth isn’t to be found by counting noses, not even expert noses; experts have been known to make mistakes.
Everybody makes mistakes. Even biologists do; even lots of biologists assembled together do; even great biologists like Darwin do. You don’t need an advanced degree to make a mistake or to spot one. You don’t need an ornithologist to tell a hawk from a handsaw. If, therefore, you think a mistake has been made, it’s a good thing to say so, loudly and in public, so that it (or you) can be corrected. We would have thought this a consensus view among scientists, philosophers, and everybody else who cares at all about distinguishing what’s true from what isn’t. The parochial is the enemy of the true and should not, therefore, be encouraged by its friends.
• • •
Ned Block and Philip Kitcher respond:
We are pleased to see that there is now so much agreement between Jerry Fodor and Massimo Piattelli-Palmarini and us. They now concede (at least in the second paragraph of their reply) that one but not the other of two correlated variables can have a differential effect on reproductive success. To use our example, dark color in the famous moths can be causally responsible for their reproductive success in polluted environments even though correlated properties have no effect on reproductive success.
Since selection-for just is identical to having a differential effect on reproductive success, one might suppose that Fodor and Piattelli-Palmarini would have to accept that dark color was selected for whereas properties correlated with the dark color were not. But they hedge their acceptance of this standard identification. For they go on to say: “Darwin needs an account of selection-for that distinguishes phenotypic traits that cause fitness [i.e. reproductive success] from traits that are merely correlated with traits that cause fitness.” We find their odd demand frustrating because as the pertinent notions are used in evolutionary theory and in philosophy of biology, traits that cause fitness just are traits that are selected for. Selection for a particular trait requires nothing further.
What is the additional requirement on selection-for over and above differential effect on fitness? Fodor and Piattelli-Palmarini’s answer: “Darwin is in need of a mechanism that responds differently to A-caused Cs on the one hand and to B-caused Cs on the other.” This is either to contradict the common understanding of selection-for as differential causation of fitness, or to take back their concession that just one of two (or more) correlated properties can differentially affect fitness.
Fodor and Piattelli-Palmarini are imposing a requirement on natural selection that no biologist or philosopher whom we know of has ever suggested.
Consider the moths. That dark color has a differential effect on fitness is sufficient to establish that dark color is selected for. There is no need for a detector mechanism to register that dark color is the cause of the increased reproductive success. Fodor and Piattelli-Palmarini write as if Darwinian evolutionary theory requires some analog of litmus paper that turns red when there is selection-for and blue when a trait is merely a free rider. But that supposed requirement is ludicrous. We mentioned Fodor and Piattelli-Palmarini’s repeated personifications of natural selection, derived from Darwin’s unfortunate attempts to explain the idea. Thus they say that natural selection (or evolution) is “insensitive to the distinction between traits selected-for and their free-riders.” Our critique charitably construed these personifications as part of a philosophical argument designed to show a supposed “intensional fallacy.” Their reply reveals a confusion much simpler than the ones we criticized in our review.
Fodor and Piattelli-Palmarini are imposing a requirement that no one else—no biologist or philosopher whom we know of—has ever suggested in the history of evolutionary thinking. The idea that, in order for dark color rather than some correlated trait to be selected for, there is a need for “a device that responds selectively” to one rather than the other is simply an eccentric invention. It is as if, having abandoned Mother Nature, Fodor and Piattelli-Palmarini think there has to be a mechanism that takes her place. As they say, “We don’t think that there is or could be such a mechanism.” Who ever thought otherwise? They continue: “We have heard of many ways of distinguishing confounded variables, and none of them will do the job.” But the job is done by causation itself. Dark color promotes progeny; no other mechanism is needed. To repeat: there is selection for a (heritable) property just in case having that property causes increased reproductive success. If Fodor and Piattelli-Palmarini have some other job in mind, they have to explain why Darwinian evolutionary theory needs that job to be done. They claim to be criticizing “natural selection, as neo-Darwinians understand it,” but instead they are criticizing a strange version of natural selection, invented solely so that it can be demolished.
So far, we would not characterize this as a “deep disagreement.” However, there is a disagreement described in Fodor and Piattelli-Palmarini’s response that is worth discussing. It concerns the idea that “a mere chronicle of instances of adaptation would not . . . amount to a theory of adaptation. It would just be ‘natural history.’”
Fodor and Piattelli-Palmarini’s charge against Darwinian evolutionary theory reduces to the observation that there is no general implementation of natural selection, no all-purpose mechanism by which one trait rather than another differentially affects fitness. In consequence, according to them, there is no theory of natural selection. Many biologists and philosophers would want to use the term “theory” rather differently from the usage Fodor and Piattelli-Palmarini favor. Some would wince at the idea that Darwin and his successors were in the business of finding some analog of a Platonic theory of beds. One of the greatest twentieth-century evolutionary theorists, Ernst Mayr, pointed out, repeatedly, that Darwin’s ideas are profoundly anti-essentialist, based on “population thinking.” But let us simply grant Fodor and Piattelli-Palmarini the word. There is no “theory” of natural selection. So what?
Evolutionary biology, from Darwin on, is concerned to understand the history of life. Evolutionary biologists want to know what transitions have occurred, how species are related, what general types of factors have played a role, and what particular causes have operated in particular instances. That is what the subject is about. Does it require any “theory” of the kind Fodor and Piattelli-Palmarini tendentiously demand?
In a word, no. For 150 years everybody in the business has known, very clearly, that cases of natural selection are diverse. The point is elementary: the natural selection of moths in polluted woods results from the causal process in which dark coloration makes for effective camouflage; the natural selection of finches in the Galapagos stems from causal processes in which beaks of different sizes and shapes enable birds to crack open seeds and thus obtain food; the natural selection of (male) guppies in streams results from causal processes in which spots on the fish are large enough to attract mates but not so large as to interest predators; and on and on and on. Any search for a universal piece of machinery implementing natural selection would be futile. Yet that makes not the slightest difference to the Darwinian project. The explanation of the history of life can proceed in just the ways it has done and continues to do, exploring the famously problematic cases (the origins of the cell, the evolution of sex), finding some general types of processes that occur with considerable frequency (kin selection, balanced polymorphisms), tracing the causes of particular transitions about which scientists (and others) are curious (increased brain size in the hominid line, the evolution of flight).
We entirely agree that these investigations can benefit from considerations of the type that Fodor and Piattelli-Palmarini review in Part I of their book (constraints, epigenetics, attention to properties of the genome, and so forth). One of us (Kitcher) has argued for decades against the naïve adaptationism that assumes the untrammeled operation of natural selection. Recognizing the ways in which the possibilities of Darwinian explanation have been enriched in recent years is, however, a far cry from declaring that natural selection is unnecessary or that the idea is incoherent. Retelling familiar things does not debunk natural selection.
The argument of the book thus depends on the charge that natural selection is incoherent. In the book itself, this is presented in terms of an “intensional fallacy,” aimed, apparently, at supposed difficulties in separating correlated traits from genuine causes of fitness. In our critique we responded to these difficulties in the most prominent forms in which Fodor and Piattelli-Palmarini present them. After our critique, Fodor and Piattelli-Palmarini have apparently decided that the crucial point is the lack of a “theory” of natural selection. But, as we have noted here, nobody needs a “theory” of the type they demand. Instead of the flawed reasoning that seemed to be leading them to a challenging conclusion, they have now shifted to an absurd demand for some uniform process that will be common to all cases in which traits cause increased reproductive success.
As “old and case-hardened” veterans, Fodor and Piattelli-Palmarini ask their readers to understand that they are aware of points made in introductory philosophy courses. We do not accuse them of not knowing (for example) about Mill’s methods. The trouble is that they are commenting on an area about which they know so little that they fail to see how basic philosophical points apply. Even the slightest awareness of fallibility might incline them to wonder if their supposedly bold attempt to spread enlightenment is really ignorant blundering that can be exploited by people whose causes they oppose.
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About the Author
Jerry Fodor is State of New Jersey Professor of Philosophy at Rutgers University and coauthor with Massimo Piattelli-Palmarini of What Darwin Got Wrong.
Massimo Piattelli-Palmarini is Professor of Cognitive Science, Linguistics, and Psychology at the University of Arizona and coauthor with Jerry Fodor of What Darwin Got Wrong.
Ned Block, Silver Professor of Philosophy, Psychology, and Neural Science at New York University, is author of Consciousness, Function, and Representation.
Philip Kitcher, John Dewey Professor of Philosophy at Columbia University, received a Lannan Foundation Distinguished Book Award for Living With Darwin.
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What's true of basketball tournaments is true of natural selection. Darwin pointed out that if you have variation, heritability, and competition, you get evolution. This is the "theory". To apply the theory, you have to fill in the details on a case by case basis. Some interesting trends emerge, to be sure, but nothing like laws of selection. The power of the theory rests on the extent to which the conditions of heritability, competition, and variation can explain what we want to explain.
Now, if this is what we should say, and if this does not undermine the scientific credentials of the theory of natural selection, then what's all the fuss about? Perhaps the problem isn't with the science, but with the philosophy of science.
Perhaps then we should try to devise an experiment to see which of us is right.
"No need", say Block and Kitcher. The idea that there must be some way of telling which of us is right ("some analog of litmus") is "ludicrous", "an eccentric invention".
They say that the job of saying which of us is right is "done "by causation itself" since whatever causes the plague is the thing that causes the plague and not the other thing.
So we don't have to do any experiments at all! Lets just be very quiet and wait for
"causation itself" to tell us who is right!
When Block and Kitcher say that "causation itself" does the job, they mean that there is no force selecting traits that will yield fitness. All we need in order to accept that natural selection (along with some other processes mentioned here and in the review) explains the evolution and differentiation of species is the recognition derived through rigorous observation (experimentation) that certain traits are associated with fitness. The "litmus" is the unneeded force.
Nowhere do Block and Kitcher say that humans can wait passively for "causation itself" to "tell" us anything. You are repeating the mistake of personifying. The thing that tells is the "eccentric invention."
Of course human investigators, in order to *learn* which of A or B caused C, will have to run experiments in order to find evidence to disentangle causation from correlation, but that is an epistemic point about human investigation, not a point about the actual cause of C.
There doesn't appear to be anything to disagree with in the reply of Block and Kitcher.
Am I missing something here?
For example, their mention of a "Platonic theory of beds" was beyond worthless. Please. K&B would be well outside the mainstream if they denied that beds have something in common with one another. That was the only point being made. (But perhaps they want to hinge their argument on nominalism and try to pedantically defend their silliness by way of the claim that objects don't have properties in common.)
F&P's main point, of course, is that where we have correlated traits (always and everywhere historically correlated), these traits are not isolable, and so we have no good reason to say that one rather than the other was selected for.
Of course, perhaps one of them WAS selected for (namely the one that played the causal role). But evolutionary speculations here are, according to F&P, epistemically irresponsible and fail to amount to a theory.
If one wants to fight with F&P, the ground on which to do so is obvious. Namely, one can first deny that these traits are historically so correlated that they are not isolable. That is, we can test for which trait caused the survial. Or, alternatively, we can just *see* which trait was responsible. Both responses hold promise. I think we can *just see* that the black color of the moths, say, was responsible for the survival of the moths, instead of, let us suppose, the always and everywhere historically correlated tiny moth right-wing blue spot.
That is, we can see that the overall blackness of the wings is the cause, or the probable cause, and we can see that the tiny hypothetical blue spot is probably not the cause. And this insight justifies our belief, even absent testing.
K&B are fighting on all the wrong grounds, and they are definitely losing this fight. But hey, keep on waving that flag, K&B!
Evolutionary explanations are historical/causal explanations of unique occurrences. e.g. how the leopard got its spots . Whenever and however the leopard got its spots, it got them only once. Maybe the spots had survival value, maybe not. But
we can't decide that by running the "leopard experiment" over and over again while permuting variables.
Compare "Obama would have won even if he had been white." Maybe this true and maybe it isn't, but you can't test this by "running controlled studies to isolate potential variables" to get ever more "precision".
This isn't how to fight F&P, for they grant all of this! Yes, WE can isolate the traits. The argument is that there is no SELECTION MECHANISM that can do this. Why not? Because either Mother Nature is attending to the relevant difference, or there are laws of selection. But there is no Mother Nature, and there are no laws of selection, i.e., no laws that subsume all and only the traits that evolutionary theories say were selected-for. They write:
"We think, by the way, that it’s no accident that the notion of selection Darwinians favor is so thin. What they want is a theory of evolution that applies to any creature in any ecology. We doubt that such a theory is possible. We think that how a creature’s trait evolved in its ecology is likely to be very sensitive to which creature it is, and which trait it is, and which ecology it is. Such facts belong to natural history which, like historical explanations in general, reveals the causal antecedents of phenomena, not the empirical necessities that subsume it."
I think the exchange between F&P and K&B is helpful insofar as it allows us to see what the dispute is. It's a dispute over what is required for something to be a scientific theory. According to F&P, in order for there to be selection-for, there has to be selection-for "as such," and if there is selection-for as such, there have to be laws which subsume the relevant traits. But there are no such laws, and so there is no selection-for as such. K&B happily concede this point, but then argue that no evolutionary biologist has ever thought otherwise.
As Kitcher & Block point out, to say that there is "selection for" some trait in some environment is just to say that the trait causes success in that environment. It's a widely used term of art that departs from the everyday usage of "selection".
Yet talk of "selection for" does make it sound a bit like there is an agent or a black-boxed mechanism "doing the selecting". Though this is not what biologists mean, a non-specialist could easily get the wrong impression.
Is that's so?
If Martin's right then it seems that whenever a Darwinan says something like
"Moths are black because that color camouflages them against birds and other predators"
What they have *really* been saying all along is:
"Moths are black because that color or some other correlated feature we don't know about or think is irrelevant that makes the moth more fit by some mechanism or other e.g. camouflage, or resistance to disease, reproductive efficiency, faster healing, faster speed, better eye sight... or who knows what else and I don't pretend to know which" .
Somehow, when you put it that way, it doesn't sound like "The greatest idea anyone has ever had".
But maybe that's just me.
"Moths are black because that color camouflages them against birds and other predators"
what they have *really* been saying all along is:
"Moths are black because that color camouflages them against birds and other predators"
F&P's objection is that the Darwinian is not permitted to say this, but the objection isn't grounded in some forlorn skepticism about our ability to discern causes. If it were, then they could have just as easily written "Against Lavoisier" or "Against Einstein" or "Against Chomsky" or...you get the point (I hope). The objection is that, in order for Darwinism to be a scientific theory, it has to be committed to more than saying just that *selected-for* traits are the traits that were causally responsible for driving evolutionary change.
What I mean to agree with is Martin's observation that the disagreement is "a dispute over what is required for something to be a scientific theory." F&P think that the scientific status of the theory of natural selection requires that certain conditions be met on what a theory is, and B&K deny those conditions. In their view any particular instance of selection will be explained in terms of the details of the case, and there is no general mechanism in all cases. In this respect it's a debate about whether this is all science requires.
"Just as Block and Kitcher say, natural selection 'make[s] a causal
claim: having the trait causes greater reproductive success.' That
being the claim, Darwin is in need of a mechanism that responds
differently to A-caused Cs on the one hand and to B-caused Cs on the
other, and that does so with no access to the endogenous structures of
organisms; indeed a device that responds selectively to A-caused Cs
and B-caused Cs even though it has access to nothing at all except
correlations between phenotypic traits and fitness."
In this discussion, the correlation between A and B is assumed to be
perfect (correlation 1.0). In this case, it cannot be expected that
the causal effectiveness of A and B can be distinguished only by using
other correlations. But the use of only other correlations to
determine which of A or B is causally effective is unreasonable, since
it assumes that natural selection should be considered in
isolation from the rest of biology and science.
http://bloggingheads.tv/diavlogs/26848
The theory of natural selection does not provide an account of the frequency of phenotypic traits per se; it only provides an account of what they call "adaptations", i.e. traits that contribute to fitness.
The argument starts with the observation that those traits that *don't* contribute to fitness - the 'free-riders', for instance - clearly *can't* be explained by natural selection.
F&PP's argument seems to be that for natural selection to be a theory of phenotypic traits' frequency *per se*, *all* phenotypic traits that evolve would therefore have to contribute to fitness. This (possible but not actual) condition would require a causal mechanism able to distinguish between traits that contribute to fitness and traits that don't. Instead, the causal mechanisms involved in evolution (unlike those involved in intentional design, for example) are unable to rule out non-fitness-enhancing traits, and free-riders appear. In other words, these causal mechanisms are unable to "select-for", resulting in traits that do not contribute to fitness and therefore cannot be explained by natural selection. So F&PP are concerned with the *fact* that causal mechanisms cannot preclude the appearance of non-adaptations because *they* cannot 'distinguish' between adaptations and free-riders, *not* (as B&K claim) with the fact that we cannot distinguish between 'adaptations' and 'non-adaptations'. (Here I think F&PP's use of the verb "distinguish" is unhelpful because personifies when in fact they're talking about a non-intentional process.)
So as a general theory of adaptation, natural selection is unhelpful. The domain of application of the theory (the class of evolutionary developments which it explains) appears to be restricted to those phenotypic traits whose prevalence *in fact* contributes to fitness. So in order to determine whether the theory applied to a given trait, we'd first have to determine whether the trait *in fact* contributed to fitness or not.
If this is true, natural selection should not be considered a "theory of evolution". It is legitimate to use it as a "theory of fitness-enhancing traits", and to apply it to those traits that have been observed to enhance fitness. But it is **illegitimate** to reverse this process and assume that *every* trait is fitness-enhancing *because* natural selection explains evolutionary processes. This just isn't Darwin.
To see that this isn't Darwin, we surely need to re-situate natural selection into the context in which it was developed - one where 'good' adaptations could be explained by appeal to an intelligent designer. Natural selection is powerful precisely because it offers an alternative explanation for *'good'* adaptations, not because it offers an explanation for all or even most phenotypic traits.
This isn't to claim - as B&K acknowledge - that natural selection needs to be "enriched" in order to understand the true complexity of evolution. Instead, this argument delivers the much stronger conclusion that Darwin's explanation was never supposed to be the lynchpin of evolutionary theory.
If I'm right in interpreting F&PP's argument in this way, I think they're onto something.
Tomkow's Theory: The US has the presidents it does because of the process of electoral selection. Electoral selection works by selecting the most popular candidates.
Presidents are popular or unpopular because of their traits. The president elected at any given time will be the president with the most popular traits.
Now I assume you agree that:
1) My theory, as far as it goes, is true.
2) There is a fact of the matter why any given president is elected.
3) Whether someone is elected president depends on some of their traits and not others.
4) The election of every president is explained by his possession of popular traits.
5) It is often obvious that certain traits at certain times make some candidates more popular than others.
6) There are plenty of clear historical examples of Tomkovian selection in action: e.g. President X was clearly selected because he had trait T and T was popular (substitute for whatever historical X and T you think clear).
7) It is perfectly clear, that as a matter of fact, some traits that may be correlated with popularity are not really electorally significant. Thus it happens that historically, the tallest candidate always wins a US election. But everyone can see, and Tomkow certainly would not deny, that tallness is not the trait that people are voting for.
8) There is a huge industry of serious and sensible people who do careful objective work in studying , explaining and predicting presidential elections using powerful statistical tools and careful historical analysis.
9) There may indeed be, and we may soon discover, real law-like regularities that connect the popularity of particular traits with specific environmental factors e.g. of the rate of taxation or GDP or …
10) There is no reason why the study of what traits lead to electoral success cannot be scientific in every sense of the word.
Okay. Now given that you agree about points 1-10, don't you concede that Tomkow's theory represents a deep, indeed profound, insight into the workings of the political order?
No? What's that you say?
You say that even though 1-10 are true, Tomkow's theory by itself, provides no clue at all about how to distinguish what traits are popular at any given time from other irrelevant traits.
You say that Tomkow's theory itself really doesn't explain why any particular candidate was or will be elected.
You say that even though historians and political scientists have lots of substantive things to say, it's really no thanks to Tomkow.
You say that Tomkow's theory of Presidential selection really isn't a Scientific Theory at all!
You know, your complaints about my theory of Presidential Selection sound an awful lot like F&P's complaints against Darwin's theory of Natural Selection.
The basic idea is that the applicability of a single mechanism to a domain is a better criterion for something’s being a theory of that domain than the universality of laws employing terms referring to that mechanism.
Had the selection of US presidents been incomprehensible to anyone before the laying out of Tomkow's rules of presidential selection I suspect your name would end up synonymous with political analysis.
You seem to have missed the fundamental point that Darwin (not alone or uniquely) explained for the first time something previously inexplicable. That is the value of Darwinian evolution.
The most powerful and valuable scientific discoveries are those which, after the fact, appear blindingly obvious.
That the US has popular elections is a large and important fact about the country. That species evolve through natural selection -- something F&P don't deny-- is a large and important fact about the natural world . It's a fact that any scientific explanation of the distribution of phenotypic traits must accommodate. F&P don't deny that either, though they deny that Darwin's account is such a theory.
As the discoverer of a fact, Darwin deserves honor; like the discoverers of the Pacific Ocean or the source of the Nile. As the discoverer of a very large and important fact Darwin deserves very great honor. It's a discovery on a bigger scale that the discovery of the circulation of blood though smaller that the discovery of the expanding universe. By that measure Darwin ranks above Harvey but below Hubble. But great though those three may be there are some of us who think that the greatest honor in science should not go to those who discover large and pervasive facts about the world -- important as those discoveries are. We think top honors and reverence should go to those who manage to subsume those large and pervasive facts under small and concise equations. Figures like Einstein, Maxwell, Newton, Dirac… Biology may someday have a such a figure. Darwin wasn't it.
Which is why some of us view the current Darwin hagiography industry with some dismay.
Darwin's great discovery, as you say, now seems "blindingly obvious". Not so Einstein's or Maxwell's. Which is why, I suppose, Darwin is such an easy "sell" for those who want to sell science as a secular religion. You can flatter the rubes into thinking that they too can effortlessly understand a Big Idea. Not a something you can easily do with Relativity or Quantum mechanics. But I fear that, in the end, these efforts to exaggerate Darwin's significance will only serve to distort and diminish public appreciation of the goals and value of science proper.
If gene A is linked to gene B and gene B is selected for under certain conditions, then gene A survives too. Therefore Gene A is adapted to survival through its link to gene B. Free loading can be an adaptation too.
It must be remembered that many genes are not manifested in the phenotype, perhaps they are recessive or do not code, but the dynamics of natural selection still acts upon them and we can see how it is resolved in the example above.
I do not believe that those biologists promoting Darwinism today would do so using the phenotype, they would use the genotype.
And then Tomkow comes along, and proposed his Theory of Presidential Selection, through careful gathering and analysis of data on presidents. He can't predict when any particular man will become president in the future, though presidential history seems to confirm this theory. Others pick up on it, and more and more historical evidence seems to fit.
Now, political scientists want to be bold, and try to predict the next president. They have somewhere to start: an electorate, a candidate, and possible popular traits. They don't get everything right, but they can make some predictions, like, for example, a candidate that would otherwise be popular was caught in a sex scandal. Some get more ambitious, and decide that they want to help a man become president. Instead of, like their predecessors had done, trying to increase "maleness" and "whiteness" of their candidates and giving them vitamins to bolster their presidential spirits, instead they seek to give him popular policies and stances, and do other things that will increase his (or her) popularity, as predicted by polling data and previous issues in the past. Others, also bold, try to investigate Congressmen and Governors in Tomkowian terms.
Now, the Tomkow Theory by itself can't predict which candidate will win, or produce winning strategies. But without the Tomkow theory, political scientists were completely lost. Thanks to the theory, they have a paradigm in which to work, a general mechanism which, though requiring a lot of additional investigation of the particulars to make predictions, will at least tell them what and how to investigate.
Well, my way of telling the story would be to imagine aliens observing the U.S. from space and trying to figure out why every few years one of its hundreds of millions takes over. We can imagine that all this might seem entirely mysterious until the alien "tomkow" proposes his theory.
Now you are right, this would be a very big deal and an indispensible first step towards the aliens making any sense of American politics. But one can acknowledge that and still recognize, as you do , that the theory *as it stands* does not explain what features of any given president make him popular or get him elected.
By analogy, FPP need not deny that Darwin's Theory was a *huge* deal and an important first step towards explaining why species have the traits they do. But they can still insist that, as it stands, what Darwin actually said *doesn't* explain that.
I have a bit more to say about this at http://www.tomkow.com
Explain the mimicry of pollinators displayed by some varieties of flowering plants without reference to natural selection. Why do some flowers look like the bees that pollinate them? What sort of generalizations can we make about the chain of events that led to such a bizarre phenotype on the part of the flower? Can we explain this without discussing the relative reproductive success of plant organisms with flowers that look more or less like bees?
Like it or not, selection arguments make sense. More importantly for its status as a scientific theory, natural selection provides ample ground for investigations of the particular phenomena that full under its heading, i.e. it suggests research programs.
Do you have anything better? Explain the flowers using something other than natural selection. Your something other should also suggest interesting areas of biological research, and should preferably do a better job than natural selection.
What you got? Anything?
they are trying to tear down a scientific paradigm without offering any sort of replacement. Are they suggesting evolutionary biologists stop doing any research that employs selection models?
Even assuming there are problems with a paradigm, and here I think the only "problems" consist of further elucidating concepts that already fall under the heading of natural selection, it can't really be abandoned without hamstringing current scientific research. And if natural selection wasn't a productive paradigm, it would probably have more competitors than zero (OK, maybe we can count ID as 0.5).
Game theory (GT) is mathematics and by definition it cannot be a scientific theory. GTal themes may show up in scientific theories as can a lot of math of course (albeit some great math cannot possibly show up despite being great!), but it's not the math what makes a model "scientific" but the direct and indirect experimental support for the ontological entities assumed by the model and for their predicted behavior and consequences. Abstract generalizations with abstract GT entities are not science but rather math.
A scientific theory like that of gravitation does include math but not only. Natural selection (NS) narratives fall between these two extremes: they mobilize a firework of circumstantial natural-historical details that are GTally relevant (in ceteris-paribus or dynamically positive ways), but abstractly speaking the winners are always “the result” of the Bauplan’s potential to be altered (due to mutation, etc) so that modified “units” show up that deal with the specific selective agent/regime better than existing units do.
This *non-exhausted* Bauplan’s potential is part of the unifying “gravity-like” force driving evolution by natural selection (EBNS), and existing GT-oriented evol.bio narratives have nothing “ontologically” comparable to offer (i.e., they have no obligate links to a unifying natural "force").
This potential of Bauplaene is part of what Van Valen went after when he proposed what he called “the 3rd law of natural selection” (1976; he meant EBNS when writing “natural selection”).
No need to say that the unifying “gravity-like” force driving NS (as opposed to that driving EBNS) cannot be studied in the same way and time scales as that driving EBNS…
All in all, the trailer-park-level understanding of what a scientific theory should be that has been put on display by most of the phil.of biol and evol.biol establishment frauds who have commented on F&PP’s “idiots-savants” book rivals non-necessarily favorably with that of the peddler of puerilo-retarded animistico-suggestive anthropomorphizations, Dawkins; and their arguments are barely less misguided and heuristically less pernicious that D’s syllogistic imbecility about “DNA with intentionality”.
Like many others before, F&PP had the gut feeling that the unifying “gravity-like” forces driving NS and EBNS are unknown and neglected, and that available NS and EBNS stories are “different for each case” (let’s celebrate diversity!) because these narratives are ontologically truncated: 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., seeing them list a litany of sufficient but *not* necessary things under selection, but never witnessing anybody mention the necessary thing which is "to avoid being killed by the predator" (but note that a narrative organized around the latter statement would still be "ontologically truncated" because it would not apply to all living systems!).
Yes, in a tired recent NYRB piece on this affair, Lewontin mentioned that F&PP have stated that they are not asking for such a unifying force/unified narrative, but the real question is whether they would have anything to grumble if the unified force/narrative were already a highly visible central concern and *the* main research focus in evol.bio.
Truly, it’s shocking to see –among “professional” philosophers of science– such ignorance of the deep epistemological canons that distinguish better-developed scientific theories from crude best-intentioned "early" narratives, and so is to see –-among “professional” evolutionary biologists– such ignorance of deep evolutionary biology.
This whole debate shows one more time what kind of charade the american system of promoting self-complacent paper-churner/grant-chaser hybrid frauds has generated…
Sure, after the fact, we can usually tease apart what caused the change of velocity and what was merely a "free rider." I'm not a dummy. I understand how physics work. I'm just saying that what Newtonists do is really just compile a history of forces. They are not doing Physics with a capital P.
In order for Newton's first law of motion to be a "theory" it must say something more than the empty statement that force "causes" a change in velocity.
I am not interested in counting the noses of the physicists and engineers who are unimpressed with my theory. I am only interested in being the guy who has shaken the very foundations of classical physics. I am available for speaking tours
The act of "selection" happens when an individual produces offspring before dying. That's what natural selection selects for - successful reproduction. Successful reproduction is influenced positively by some traits, but there is no hard and fast rule as to which traits lead to reproductive success. Some traits make it more likely, some make it less, and some have no discernible effect, but no trait can guarantee success or failure, because individuals are sometimes lucky or unlucky.
The theory of evolution deals with how the reproductive success of individuals is made more likely by certain traits, and how this reproductive success leads to the traits of those individuals becoming more common in the population as a whole. For this reason, we often say that traits are "selected for", but in this case it is not an individual act of selection to which we are referring, but to the overall tendency of individuals with such a trait to be more successful in reproduction, and to therefore be selected. What we mean is that individuals with such a trait are more likely to be selected. Any biologist worth their salt understands this distinction.
In short, then, the mechanism of natural selection doesn't need to discern between coextensive traits because the mechanisms of reproduction and death do this (not absolutely consistently, but consistently enough). The mechanism of selection need only select for reproduction before death, which it is quite capable of doing.
However, I think this argument is a problem only for the scientific realist, who takes causation and laws to be real characteristics of the universe. I don’t believe it’s a problem for empiricism of the type that David Hume espoused. The Humean empiricist takes causation and laws to be nothing more than constant conjuctions or correlations between events in sense experience. Thus, the distinction between a phenotypic trait being a ‘cause’ of fitness and its non-causal correlates would not be a real distinction for the Humean empiricist, since both are merely correlations between events, with some correlations being ‘stronger’ than others. For the empiricist, this is all that is needed for theory construction – namely, strong or weak correlations between events. Bestowing the term ‘necessary cause’ upon any of these correlations really ads nothing to our scientific explanations other than bloating one’s ontology; ‘cause’ is merely an empty honorific.
It is not an esoteric problem for the sophist, it is a real problem that undermines the whole field of evolutionary biology.
I can't think of another field that remotely calls itself scientific where you can get away with these kind of explanations, sold with a straight face as scientific, year in and year out.