1500 words

Adaptationism is the main school of evolutionary change, through “natural selection” (NS). That is the only way for adaptations to appear, says the adaptationist: traits that were conducive to reproductive success in past environments were selected-for their contribution to fitness and therefore became fixated in the organism in question. That’s adaptationism in a nutshell. It’s also vacuous and tells us nothing interesting. In any case, the school of thought called adaptationism has been the subject of much criticism, most importantly, Gould and Lewontin (1972), Fodor (2008) and Fodor and Piatteli-Palmarini (2010). So, I would say that adaptationism becomes “rampant” when clearly cultural changes are conflated as having an evolutionary history and are still around today due to being adaptations.

Take Bret Weinstein’s recent conversation with Richard Dawkins:

Weinstein: “Understood through the perspective of German genes, vile as these behaviors were, they were completely comprehensible at the level of fitness. It was abhorrent and unacceptable—but understandable—that Germany should have viewed its Jewish population as a source of resources if you viewed Jews as non-people. And the belief structures that cause people to step onto the battlefields and fight were clearly comprehensible as adaptations of the lineages in question.”

Dawkins: “I think nationalism may be an even greater evil than religion. And I’m not sure that it’s actually helpful to speak of it in Darwinian terms.”

I find it funny that Weinstein is more of a Dawkins-ist than Dawkins himself is (in regard to his “selfish gene theory”, see Noble, 2011). In any case, what a ridiculous claim. “Guys, the Nazis were bad because of their genes and their genes made them view Jews as non-people and resources. Their behaviors were completely understandable at the level of fitness. But, Nazis bad!”

What a ridiculous claim. I like how Dawkins quickly shot the bullshit down. This is just-so storytelling on steroids. I wonder what “belief structures that cause people to step onto battlefields” are “adaptations of the lineages in question”? Do German belief structure adaptations different from any other groups? Can one prove that there are “belief structures” that are “adaptations to the lineages in question”? Or is Weinstein just telling just-so stories—stories with little evidence and that “fit” and “make sense” with the data we have (despicable Nazi behavior towards Jews after WWI and before and during WWII).

There is a larger problem with adaptationism, though: adaptationist confuse adaptiveness with adaptation (a trait can be adaptive without being an adaptation), they overlook nonadaptationist explanations, and adaptationist hypotheses are hard to falsify since a new story can be erected to explain the feature in question if one story gets disproved. That’s the dodginess of adaptationism.

An adaptationist may look at an organism, look at its traits, then construct a story as to why they have the traits they do. They will attempt to think of its evolutionary history by thinking of the environment it is currently in and what the traits in question that it has are useful for now. But there is a danger here. We can create many stories for just one so-called adaptation. How do we distinguish between which stories explain the fixation of the trait and which do not? We can’t: there is no way for us to know which of the causal stories explains the fixation of the trait.

Gould and Lewontin (1972) fault:

the adaptationist programme for its failure to distinguish current utility from reasons for origin (male tyrannosaurs may have used their diminutive front legs to titillate female partners, but this will not explain why they got so small); for its unwillingness to consider alternatives to adaptive stories; for its reliance upon plausibility alone as a criterion for accepting speculative tales; and for its failure to consider adequately such competing themes as random fixation of alleles, production of nonadaptive structures by developmental correlation with selected features (allometry, pleiotropy, material compensation, mechanically forced correlation), the separability of adaptation and selection, multiple adaptive peaks, and current utility as an epiphenomenon of nonadaptive structures.

[…]

One must not confuse the fact that a structure is used in some way (consider again the spandrels, ceiling spaces, and Aztec bodies) with the primary evolutionary reason for its existence and conformation.

Of course, though, adaptationists (e.g., evolutionary psychologists) do confuse structure for function. This is fallacious reasoning. That a trait is useful in a current environment is in no way evidence that it is an adaptation nor is it evidence that that’s why the trait evolved (e.g., a trait being useful and adaptive in a current environment).

But there is a problem with looking to the ecology of the organism in question and attempting to construct historical narratives about the evolution of the so-called adaptation. As Fodor and Piatteli-Palmarini (2010) note, “if evolutionary problems are individuated post hoc, it’s hardly surprising that phenotypes are so good at solving them.” So of course if an organism fails to secure a niche then that means that the niche was not for that organism.

That organisms are so “fit” to their environment, like a puzzle piece to its surrounding pieces, is supposed to prove that “traits are selected-for their contribution to fitness in a given ecology”, and this is what the theory of natural selection attempts to explain. Organisms fit their ecologies because its their ecologies that “design” their traits. So it is no wonder that organisms and their environments have such a tight relationship.

Take it from Fodor and Piatelli-Palmarini (2010: 137):

You don’t, after all, need an adaptationist account of evolution in order to explain the fact that phenotypes are so often appropriate to ecologies, since, first impressions to the contrary notwithstanding, there is no such fact. It is just a tautology (if it isn’t dead) a creature’s phenotype is appropriate for its survival in the ecology that it inhabits.

So since the terms “ecology” and “phenotype” are interdefined, is it any wonder why an organism’s phenotype has such a “great fit” with its ecology? I don’t think it is. Fodor and Piatteli-Palmarini (2010) note how:

it is interesting and false that creatures are well adapted to their environments; on the other hand it’s true but not interesting that creatures are well adapted to their ecologies. What, them, is the interesting truth about the fitness of phenotypes that we require adaptationism in order to explain? We’ve tried and tried, but we haven’t been able to think of one.

So the argument here could be:

P1) Niches are individuated post hoc by reference to the phenotypes that live in said niche.
P2) If the organisms weren’t there, the niche would not be there either.
C) Therefore there is no fitness of phenotypes to lifestyles that explain said adaptation.

Fodor and Piatteli-Palmarini put it bluntly about how the organism “fits” to its ecology: “although it’s very often cited in defence of Darwinism, the ‘exquisite fit’ of phenotypes to their niches is either true but tautological or irrelevant to questions about how phenotypes evolve. In either case, it provides no evidence for adaptationism.”

The million-dollar question is this, though: what would be evidence that a trait is an adaptation? Knowing what we now know about the so-called fit to the ecology, how can we say that a trait is an adaptation for problem X when niches are individuated post hoc? That right there is the folly of adaptationism, along with the fact that it is unfalsifiable and leads to just-so storytelling (Smith, 2016).

Such stories are “plausible”, but that is only because they are selected to be so. When such adaptationism becomes entrenched in thought, many traits are looked at as adaptations and then stories are constructed as to how and why the trait became fixated in the organism. But, just like EP which uses the theory of natural selection as its basis, so too does adaptationism fail. Nevermind the problem of the fitting of species to ecologies to render evolutionary problems post hoc; nevermind the problem that there is no identifying criteria for identifying adaptations; do mind the fact that there is no possible way for natural selection to do what it does: distinguish between coextensive traits.

In sum, adaptationism is a failed paradigm and we need to dispense with it. The logical problems with it are more than enough to disregard it. Sure, the fitness of a phenotype, say, the claws of a mole do make sense in the ecology it is in. But we only claim that the claws of a mole are adaptations after the fact, obviously. One may say “It’s obvious that the claws of a mole are adaptations, look at how it lives!” But this betrays a notion that Gould and Lewontin (1972) made: do not confuse structure with an evolutionary reason for its existence, which, unfortunately, many people do (most glaringly, evolutionary psychologists). Weinstein’s ridiculous claims about Nazi actions during WWII are a great example of how rampant adaptationism has become: we can explain any and all traits as an adaptation, we just need to be creative with the stories we tell. But just because we can create a story that “makes sense” and explains the observation does not mean that the story is a likely explanation for the trait’s existence.