Fodor and Piattelli’s (2011) book “What Darwin Got Wrong” has been savagely reviewed in the literature. I share this negative view of the book though I do think that it is far superior to Nagel’s (2012) “Mind and Cosmos”. Fodor and Piattelli at least try to engage with the technical literature on evolutionary theory while Nagel makes no attempt to meet this basic requirement. That said I still am not convinced that the empirical evidence or conceptual evidence provided by Fodor and Piattelli supports their radical conclusion. In this blog I will summarise the arguments in “What Darwin Got Wrong” and show where I think they go wrong.
The book has two different parts. Part one is a review of biological evidence which purports to show that Natural Selection plays a much smaller role in biology than is admitted by proponents of Darwinian theory. To show this they review evidence from the Evo-Devo revolution in biology, internal constraints in biology, laws of form etc. In the second part of the book they give a conceptual argument which they claim shows that the theory of natural selection is inprinciple incapable of explaining what it purports to explain. Both parts of the book are logically independent of each other and can be assessed seperately. They begin their book by comparing the theory of natural selection (TNS), with B. F. Skinner’s theory of learning by operant training (OT). Fodor and Piattelli in effect argue that Skinner’s theory and Darwin’s theory have the same logical structure, but while nobody today believes Skinner everybody believes Darwin. They argue that since the TNS is subject to the same weakness as OT people should reject the TNS in the same way they reject OT.
Before discussing their claims about TNS I want to make some quick points about their claim that OT is accepted by nobody. This is not really true, behaviourism is largely lampooned by the cognitive science community. However outside of this community it is still to some degree accepted. Behavioural techniques are very effective for helping autistic children who are having difficulties learning language. Furthermore a lot of the arguments used against behaviourism in particular those which originate from Chomsky have not stood the test of time. Firstly because Chomsky did not really understand what the claims made by behaviourists amounted to. Secondly because a lot of poverty of stimulus arguments used to discredit behaviourism have been discredited. I have discussed Chomsky and behaviourism in detail in an earlier blog so won’t go into it here. I merely want to note that Fodor and Piattelli’s views on OT are really a caricature of the position, I will argue that the same is true of their views on evolutionary theory. Firstly I will make clear exactly what the analogy between OT and TNS is for Fodor and Piattelli.
The first point of comparison they make is in terms of what they call population thinking. They claim that a way to think of TNS is as a theory of how phenotypic properties of populations change overtime in response to ecological variables (pg3). They define OT in a similar way ‘OT is plausibly is also plausibly viewed as a black box that maps a distribution of traits in a population at a time ( a creatures behavioural repertoire at that time), together with a specification of relevant environmental variables (viz. The creature’s history of reinforcement), onto a succeding distribution of traits).
They argue that the TNS and OT have 6 basic untenable feature in common: (1) Iterativity: ET provides no bounds on the type of phenotype possible OT provides no bounds on the variety of behavioural profiles which can be created through conditioning.(2) Environmentalism: ET and OT abstract from endogenous variables, claiming that the phenomenon of evolution on the one hand and psychology on the other are largely the effects of environmental causes (3) Gradualism: ET argues that new phenotypes emerge gradually, OT argues that learning is a gradual process of stimulus response conditioning (4) Monotonicity: ET and OT are one factor theories. For ET selection does all the work. For OT conditioning does all the work. (5) Locality: Both ET and OT are local processes and are insensitive to mere hypothetical contingencies (6) Mindlessness: ET doesn’t postulate God to do the work and OT doesn’t postulate Mind to do the work.
Fodor and Piattelli argue that the evidence they provide in the two parts of their book shows that evolutionary theory as defined according to the above six principles cannot do what it purports to do. I will argue that they are simply misrepresenting evolutionary theory. There is no reason to hold evolutionary theory to principle 1, 2 or 4.
The first part of Fodor and Piattelli’s book is the biological argument. As I mentioned before the truth of this part is logically independent of the truth of part two. Part one is divided in to four chapters. The four chapters are as follows: (1) Internal Constraints: What the new biology tells us, (2) Whole genomes, networks, modules and other complexities, (3) Many contraints, many environments, (4) The return of the laws of form. I will now consider the evidence he puts forth in part one. It is important to note that the arguments in part 1 only purport to demonstrate that NS does not play as big a role as theorists like Maynard-Smith, Dawkins and Dennnett think it does. This part does not make any claim that NS is an incoherent concept, that particular claim is supposedly justified in part 2.
Chapter one: Internal constraints: The authors begin this section with a claim that standard Neo-Darwianists are environmentalists by definition. By this they mean that standard Darwianian theory thinks that changes to a phenotype are largely driven by environmental contingencies. Their primary aim in this section is to show that contemporary wet biology is telling a story of innate constraints which are at odds with the neo-darwinian story. It is worth noting that the authors they cite in this section do not agree with the use Fodor and Piattelli make of their work ( Fodor and Piattelli acknowledge this point). Furthermore, most neo-darwianians would deny that they are environmenalists in Fodor and Piattelli’s sense. So they would argue that Fodor and Piattelli are attacking a strawman. To this Fodor and Piattelli reply by citing a variety of neo-darwianians who do indeed seem to support strict environmentalism.
Bearing all of this in mind lets now review the evidence they cite. The first thing they cite is the concept of Unidimentionality. Unidimentionality is supposedly standard story in the neo-darwinnian theory. On this picture NS plays the primary role in the theory of evolution, the role of internal sources of variance, and internal constraints is said to play only a marginal role. To prove this point they cite Earnest Mayr’s book ‘Animal Species and Evolution’ as an example of such ultra-selectionist attitudes. Fodor and Piattelli claim that discussions of the evolution of the eye nicely illustrates the neo-darwinian emphasis on NS as the primary source of design in species. It was claimied by most neo-darwinian theorists that the evolution of the eye emerged several times independently and convergently across species. In his Darwins Dangerous Idea Dan Dennett referred to the evolution of the eye as a nice trick, something that was bound to be selected in any form it occured in. Dawkins has made similar claims. Fodor and Piattelli pointed out that the discovery of master genes for eye development (Pax 3, Pax 2, Pax 6, and Dach) across vastly different classes and species has shown the neo-darwinain view to be incorrect. The next topic they consider is beanbag genetics. Here they basically argue that selection for a particular gene rarely, if ever occurs, and this is because of the convoluted packing of genes in chromosomes. Their critique of beanbag genetics is a pointless because nobody believes it anyway.
One of the key factors they believe counts against the neo darwianan view is the existence of Internal Constraints and Filters. The discussion of internal constraints and filters involves an appeal to results in the evo-devo revolution. Again it is worth noting that most people working in evo-devo consider themselves a part of neo-darwinanism and would not accept the conclusions drawn from their work by Fodor and Piattelli. According to Fodor and Piattelli, the standard neo-darwinian picture abstracts away from the all effects of development on visible traits (p.27). They stress that the evo-devo revolution shows that this development not only cannot be abstracted away from, it is key to the process of evolution. The argue that it has been shown in the lab (1) phenotypic convergence is, more often than not the result of developmental constraints, (2) Also they cite the fact that experimental evidence (Ronshaugen 2001), has shown that terminal forms can differ in massive ways as a result of slight variations in the regulation of the same gene complexes/or the timing activation of such complexes (pg 30). This shows that contrary to neo-darwian claims evolution is not primarily driven by exogenous factors but by internal developmental constraints. The spend the rest of the chapter outlining a series of facts which they claim further develop their point. Throughout section 1 they are merely attacking a strawman, because most evolutionary theorists do not deny what they are claiming. Though it is true that a lot of pop science is guilty of making claims of the type they critique.
In chapter two and three Fodor and Piattelli argued that there are internal constraints which limit the importance of selection, and they considered how if at all selection could operate given these limits. They claimed that in response to the evidence reviewed in chapters two and three neo-darwinists have expanded its scope and invoked other kinds of natural selection. This chapter is an attempt to provide more problems for neo-darwinianism. The first problem they consider is the phenomenon of adaptation without selection, Fodor and Piattelli summarise the point as follows:
“The point to keep your eye on is this: it is possible to imagine serious of alternatives to the traditional Darwinain consensus that evolution is primarily a gradualistic process in which small phenotypic changes generated at random are then filtered by environmental constraints. This view is seriously defective if, as we suppose, the putative random variatons are in fact highly constrained by the internal structures of evolving organisms. Perhaps it goes without saying that if this internalist story is true, then less work is left for appeals to natural selection to do.” (What Darwin got Wrong p. 54).
They provide eight pieces of evidence which they think support their conclusion:
(1) Gene Regulatory Networks: Building from the work of E. H. Davidson (2006), they argue that gene regulatory networks are at work in the development of the organism. These gene regulatory networks are modular in nature (in other words they form compact units of interaction which are seperate from other similar units). The important point about these regulatory networks is that they are supposedly responsible for the development of the bodily structures of animals. This happens because large effect mutations acting on conserved core pathways of development. They claim that this process makes it virtually impossible to argue that particular isolated traits are selected for.
(2) Entrenchment: They claim that this acts as an engine of development and evolutionary change, and as a constraint (ibid p.43). Some evolutionary factors may be highly conserved and protected against change. They offer very little evidence of their views at this point merely a promsary note to develop the point in the next chapter.
(3) Robustness: This is the persistence of a trait of an organisism despite developmental noise, environmental change or genetic change. This robustness is important for the stablility of phenotypic change despite genetic and non-genetic variation. They site the work of Wagner (2008) which claims that it is only the additive component of genetic variation which responds to selection. Fodor and Piattelli argue this fact should make people wary of accepting the neo-darwinian view that selection is the primary vehicle of phenotypic variation.
(4) Master genes are our ‘Masters’: They make the now well established point that many genes are indissociably controlled the same ‘master gene’. Therefore if a mutation effects a master gene (and is viable) it will effect all of the genes the master gene controlls aswell. They link this to Gould’s famous paper on spandrels. They briefly discuss how the evolution of language may not be explicable interms of a simple adaptative story in terms of selection for communication. Using facts about master genes they argue that language may have been a free-rider, which was selected because some mutation in the master gene Otx. They claim that this story is not even considered because of alligence to an ultra adaptationist model. I do not agree with this claim there has been ample debates on this topic. See Hauser, Fitch and Chomsy 2005 and reply by Jackendoff and Pinker 2006. However evaluating this debate would take a long discussion of linguistics which is beyond the scope of this discussion.
They go on to further discuss things like developmental modules, coordination, morphogenetic explosions, plasticity and the (non-transitivity) of fitness. All of these facts are well known in the literature and it is unclear to me at least why they believe these facts pose a major problem for evolutionary theory. They do pose a problem for the caricature of evolutionary theory they present at the beginning of their book but not for evolutionary theory as it is actually practiced.
They also consider ‘Laws of Form’ as an argument against the standard Neo-Darwinian Story. They discuss the work of thinkers like Stewart Kauffman, Stuart Newman, and Lewis Wolpert who have all discussed the important topic of laws of form and self-organisation. Fodor emphasises how this research shows that we need to discover what forms are possible for an organism to take before we attack the question of how selection can act on these possible forms. These constraints on possible forms are shown in things like non-genomic Nativism discussed by people like Cherniak. Cherniak details computational constraints on brain anatomy which he claims are derived from physics for free; hence we do not need natural selection to explain some of the structure of the brain. Fodor and Piattelli also discuss the work of James Marden who has detailed physical constraints on possible animal locomotion. Their discussion of laws of form is extremely interesting but again it is hard to see that it really poses any problem for the standard neo-Darwinian picture. There really is nobody, and I mean nobody who denies that there are physical constraints at work in evolutionary theory. They are correct to note that pop evolutionary writers sometimes ignore these physical constraints and focus entirely on selection. So, if Fodor and Piattelli were merely warning against this type of mistake, then their point would be well made, but it should be obvious that their arguments do not have any bearing on neo-Darwinian theory when construed correctly.
As can be seen by my discussion of part 1 of their book they offer some interesting empirical research which does indeed cast doubt on some extremely weak pop-evolutionary theory, however it leaves actual neo-Darwinism untouched. Ultimately part 1 of their book can be dismissed as a largely successful attack on a straw-man. The second part of What Darwin Got Wrong is much more controversial in this part they attack Natural Selection arguing that it is an incoherent concept. Their argument in part 2 is a conceptual argument and has drawn a lot of criticism from both philosophers and scientists. Even Tom Nagel who largely agrees with Fodor and Piattelli’s argument in part 1 of the book thinks that part 2 is a bad argument. So Fodor and Piattelli cannot even rely on Nagel who thinks there is a lot wrong with the Neo-Darwinian materialism to support their more radical claims. I am not very impressed with their argument in part 2 of the book, I will firstly summarise it before offering some criticisms.
Their argument centres on the distinction between selection and selection-for. If an organism has two traits T1 and T2 which are co-extensive, for example, T1 is the heart pumping blood and T2 is the heart making thump thump noises, anytime T1 is selected T2 will be selected as well. We as theorists know that it is obviously the heart pumping blood which is selected and not the thump thump sound. The thump thump sound is merely a free-rider and isn’t the object of selection. Fodor and Piattelli note that since the traits are co-extensive then there is nothing “mother nature” can do to distinguish between them. From this fact they draw the conclusion that selection-for does not occur. They argue that only way such selection-for could occur is if “Mother Nature” has a mechanism which it can use to distinguish between such co-extensive traits. Since there is no plausible account of such a mechanism they argue that we must conclude that selection-for does not occur.
The standard reply to this argument is one of incredulity. It is perfectly true that “Mother Nature” does not select for trait x over trait y: firstly there is obviously no such thing as “Mother Nature”, secondly selection-for is more of an explanatory heuristic than something we expect to find in nature. It is evolution 101 that selection-against is what occurs not selection-for; random mutations which don’t have survival value will not be passed onto the next generation (so in this sense are selected-against), whatever isn’t selected against we sometimes describe as a trait which has been selected-for. The point is we do not need the selection-for concept to make sense of evolutionary history, selection against is enough, we can describe this process well enough using statistical models of what traits tend to survive in what environment.
To this Fodor and Piattelli would reply that the concept of selection-for is used all of the time in evolutionary theory (in particular by evolutionary psychologists). In an appendix at the end of “What Darwin Got Wrong” they provide 28 quotes from 14 different philosophers and evolutionary psychologists who are appealing to selection-for despite the fact that Fodor and Piattelli think they have shown that the concept does not do any explanatory work.
It is worth stressing again Fodor and Piattelli are not denying that there is a fact of the matter as to whether the heart pumping blood, or the heart making thump thump noises is selected. Rather they are merely asserting that since we have no plausible mechanism that “Mother Nature” can use to select for trait 1 as opposed to trait 2 then Evolutionary Theory as currently conceived cannot explain what it purports to explain.
They think that Evolutionary Theory is really just a form of historical explanation. This is nothing wrong with historical explanations per se. Calling something a historical explanation doesn’t amount to a claim that the subject matter of evolutionary theory cannot give us true theories. In historical studies we can discover facts of the matter about who the first president of America was, what year did the French revolution occur in etc. Likewise Fodor and Piattelli argue that we can discover facts of the matter about the genealogy of the species using naturalistic observations and historical explanations. They just believe that the theory of natural selection is not a strong enough tool to support the type of nomological explanations typically found in the natural sciences.
It is really difficult to know what to make of Fodor and Piattelli’s claims on selection-for. It seems to amount to nothing more than pointless hair-splitting. All of the theorists whom they quote from do indeed use selection-for in their various different theories. However their views can be trivially re-described in terms of selection against and therefore avoid the criticisms which Fodor and Piattelli bring to bear. Furthermore, Fodor and Piattelli’s distinction between historical sciences and the hard sciences is a bit antiquated and may have made sense a hundred years ago but science is much more pragmatic and problem based these days and their distinction his little relevance that I can see.
Overall, I think that all their book did, was point out some over simplifications which are given in some popular evolutionary explanations, but they have not really done any damage to evolutionary theory properly conceived as far as I can see. I will return to how Fodor’s incorrect view on the nature of the mind lead him to his strange views on evolutionary theory when I discuss how methodological dualism applied to the mind is infecting Nagel, Fodor and Plantinga in their thinking on evolutionary theory in the forth blog of this series.