Selectionism

The very idea of evolution by natural selection can have a crystallizing effect when you first embrace the implications. Like certain forms religious or poetic exegesis suddenly a multitude of details now begin to make sense in the light of natural selection. The selectionist account has a wonderful way of letting specific solutions emerge from the repeated interaction of internal (population dynamics) and external (trials posed by the environment). Some versions of adaptationism take this aroused sense of seeing connections further and invite us to make meaning and provide a selectionist account for every facet of the tangled bank — a heroic story about the genesis and maintenance of every trait and the distribution and abundance of every taxon. Critical explanation and analysis must always balance, however, between reading out of a text, exegesis, and reading into it, eisegesis.

The position that is sometimes (too quickly) labeled “anti-adaptationism” aims to embrace the way that evolution explains the distribution and abundance of forms without asserting that every (and any) detail is proof of the theory. The problem for, so-called, anti-adaptationists is that they do not stand in opposition to adaptation and natural selection. A better name for them would be a return to the well worn ‘evolutionists.’ It may be too late to wrest this word back from the caricature that synonymizes selection with evolution but ‘evolution’ has served well in the past and the use of this inclusive term should settle rather than ruffle feathers. Rather than adaptationism and evolutionism being two sides of a coin, evolutionism is a coin purse happy to have a few shiny adaptationist pennies in the mix.

This pluralistic position is so reasonable that you might think that it would be the default among evolutionary biologists. And it is, except in a few influential popularizations. This only becomes a concern when the caricature is presented as state of the art and then pressed into service (unwittingly) in allied fields (psychology, philosophy, sociology). Even then it might be unnecessary to attempt a corrective except that the marriage of functionalism (understanding parts of nature by ascribing functions to them) married to this kind of selectionist account too often becomes stridently universal. Particularly, the assertion that this is the only legitimate starting point for theories of psychology and sociology deserves to be resisted.


Seeing the world in a grain of truth

Presenters of selection theories often reach for universal application. When they do, critics call this hyper-adaptionism or ultra-Darwinism and supporters may call the exercise full-throated adaptationism. In the domain of universal applicability, selectionism’s appropriate bedfellows are other universal theories; special creation, design theories, psycho-analysis, and some economic and political theories. But this feature of explaining everything (and anything) strikes many critics of this approach as a program bug. Still, Dawkins waxes about universal Darwinism, Dennett about selectionism as a universal acid and the new sociobiologists are intent on explaining all human behavior with this same universal selection theory. Critics of such a totalizing (and at the same time narrow) position prefer the fine brush strokes of detailed explanation.

The embrace, by vocal popularizers, of this theory of everything results in evolutionists standing between Darwinian universalists on the one hand and special creationists on the other. We find ourselves having to listen to the two sides yelling at and often past each other. Unfortunately, ultra-selectionists who spend time and energy tilting at windmills of creationism assume that any request to sit down in front and stop shouting must be coming from the opposite camp. This is analogous to the haptic illusion that comes from moving your hand from cold water into lukewarm water and perceiving it as uncomfortably hot. Often, as in this essay, the criticism is just a request to leave the broad brush to those who do not have the attention span for the details of this enterprise.

I have had the experience of listing various complaints with an adaptationist presentation only to have the author respond with a kind of dismayed and disgruntled, “You talkin’ to me?” The various components of a full blown account of natural selection, which I will rehearse below, are quite uncontroversial and may even be endorsed by the target of my criticism. I will put aside the possibility that this agreement is superficial, merely the rhetorical gambit of acceding to points to confuse the debate. Upon reflection there really is broad agreement; people are not just marionettes hanging from their genes, genes really are complicated (more so each year), selfishness was an ill-advised word to be affixed to genes, and adaptationists do not intend to simply read their own class and gender interests into narratives falsely buttressed with scientific sounding claims… then why all the heat?

Some of the pop-adaptationists’ shock at being accused of caricature is feigned. Much of the critical response to their position could be fashioned from a selective reading of the adaptationist popularizations themselves. Caveats live in footnotes and quiet paragraphs as shadows within the text. This allows the author coverage by backing away again and again from more vulgar claims that populate opening paragraphs and chapter titles. Some of what is roundly criticized is there really just as a grab for attention — the shock value of it all. It turns out, for example, that even Dawkins does not think that what geneticists call ‘genes’ are what any of us call ‘selfish.’ The retreats that pepper these manifestos are in line with or anticipate some of the critiques. This makes it difficult to argue since we can spend pointless hours deconstructing. Unfortunately arguments about authorial intentions and impact will not be resolved by either critics or supporters of a distended adaptationist program.

Another aspect of the public debate that explains the acrimony is that gene-centric adaptationism is tied, by common “socio-intellectual” descent, to eugenics and the fascism that cradled those theories. There is an understandable sensitivity to the political implications of theories that have in the past been used to naturalize those social relations that so many have fought to challenge. This really should not surprise the adaptationists. Much of adaptationist storytelling is about naturalizing the status quo (since it purports to explain, by appeal to the fittest, how we came to be what we are). This sort of thing obviously plays into the hands of those who are content with where they are. Again, adaptationists should not be surprised that their positions are pressed into political service or that people notice and object to this use. At the same time, they should not be blamed for the political uses or the status quo.

Richard Dawkins’ screed against group selection, The Selfish Gene, was really an argument about ethology. It is becoming far too easy to critique the beads on a string genetics that was pressed into service for that debate. The resultant gene centrism was never particularly representative of what geneticists and molecular biologists understood as the relationship between DNA and phenotype. This is only more true now than it was decades ago. Molecular biologists are ever more impressed with how interconnected and complicated genetic dynamics are. We are now able to measure the levels of RNA and protein representing thousands to tens of thousands of genes in a tissue or group of cells. These technical advances as much as any principled stand against caricature is ushering the misleading locution of “gene for …” out of the technical literature. The popular literature will catch up.

The current application of adaptationism to sociology is called Evolutionary Psychology. It was supposed to avoid the easy racism that fit neatly into previous versions. It does this by concentrating on human universals rather than intergroup differences. There is still a lot of room for sexist just-so stories. In the domain of human universals we see the real challenge. Selectionist accounts depend on variation. If a trait really is universal in the group of interest, then, as selectionists, we should have precious little to say about it. Unless we allow ourselves to be tempted to assume that the very fact of being universal reflects the best and only surviving variant of a no longer visible diversity. Once we have taken that step we can then call on stabilizing selection to explain the continued impoverished variance. This is the game of push the selectionist account back in time until it applies (then stop). In this approach traits demand a story and if we look hard enough and at the right time we will find one. Does sexual reproduction require an explanation within the lineage of mammals beyond the observation that this trait was well established in the common ancestor? No. Unless there is actual variance around a trait selectionist accounts ought to remain completely mute. Pop-adaptationism is rarely mute and this brings on the critics.

Selectionist accounts can be too easy. Navigating around recalcitrant examples is abetted by two expectation managers; sexual selection and kin selection. These allow initial failures of theselectionist story to be recast as successes. Traits need not favor the individual, rather they might be used to attract mates (e.g. cumbersome feather displays) or they may be good for offspring, siblings or cousins in an intricate bookeeping of relations whose actual calculation is never explained. This is not a minor achievement. Having a theory with these built in accommodators makes this approach wonderfully plastic. Even Helena Cronin in her enthusiastic book on the subject is good enough to admit that when it comes to sorting out whether sexual selection is based on aesthetic sensibilities or if attraction to ornaments is simply a surrogate for a more sensible choices (beauty connected with health and vigor), “we still don’t know” and “the difficulties are largely methodological.” She is right, these theories, laden with wiggle-room, are rich with methodological difficulties.

In a way this kind of accommodating flexibility is even more pernicious than the special creationist account that at least begins to partition explanations of the described world; into the natural and the miraculous. Is this division an acknowledgement that single answerism is no answer at all? Selection-only adaptationism too often leaves us with the impression that absolutely no partitioning into kinds of explanation is necessary since any example can be given its selectionist rationalization. Of course two buckets is hardly better than one. And if indeed as skeptics suggest the natural/supernatural division merely separating the explained and the not-yet explained then maybe there is less proliferation of buckets than I want to see. Darwinian selectionism has always be a suite of explanations much of this plurality is stripped off in what I have been describing.

The history of life may correctly be just a cascade of densely packed moments with structure (heroes, agendas and progress) only imposed in retrospect. But many people resist the idea that the Proustian details are the story. Stories, after all, have morals. Can they admit chance? Once we are telling, we impose a narrative to supply the backdrop against which we can learn lessons and test our own failures and accomplishments. But even as myth makers the adaptationists fall short. They offer us always the same lame stories; always about sex but leeched of thrumming hearts and hands by an accountant’s assessment of consanguinity (calculating inclusive fitness).Their predictable characters, rapacious men and demure women, only reinscribe tired biases.

These are some of the reasons that there is still heated argument in the face of stipulated agreement to so many of the biological details. It is not the details are that are under contention. The details have been glossed in order to build a universal theory, and this spongy universalism does not stand or fall on any details, so the details become unimportant. Universal Darwinism illustrates the damage that is done to Darwin’s theory when it is hijacked and narrowed into the a priori claim that every trait can be retroactively told as a heroic tale of adaptations.