A philosopher tells us how to think clearly about evolutionary causes ... avoid adaptationism

I think philosophy has lost its way. The discipline gives credence to religious philosophers who write about god(s) and to other philosophers who reject determinism and think the mind-body problem is still an open question. Philosophers still debate the validity of the ontological argument. Philosophers of science have not even settled the question of what is science, let alone come up with a valid answer of how to do it. There are few other disciplines that are still respected after several hundred years of trying, and failing, to answer the most fundamental questions in their field. Many academic philosophy department are hotbeds of political correctness and just plain politics.

The most valid part of modern philosophy is logic. That's the part that absolutely must be taught in schools as early as possible. It's the basis of critical thinking.

Some scientists have a much better appreciation of philosophy. That's probably because they have worked closely, and successfully, with one or two of the best. I sympathize with those scientists because I also know some very good philosophers who have provided crucial insight into some serious problems in biology. I won't name them all (Hi John!) because I might forget one or two.

I think Stephen Jay Gould struck the right balance when he wrote the following passage in The Structure of Evolutionary Theory (pp. 28-29).

Most of us would scoff at the prospect of working with a professional philosopher, regarding such an enterprise as, at best, a pleasant waste of time and, at worst, as admission that our own clarity of thought had become addled (or at least a fear that our colleagues would so regard our interdisciplinary collaboration).

An yet, the conceptual problems presented by theories based on causes operating at several levels simultaneously, or effects propagated up and down, of properties emerging (or not) at higher levels, of the interaction of random and deteministic processes, and of predictable and contingent influence, have proven to be so complex, and so unfamiliar to people trained in the simpler models of causal flow ... that we have to reach out to colleagues explicitly trained in rigorous thinking about such issues.....

My own understanding of how to formulate an operational theory of hierarchical selection, and my 'rescue; from a crucual conceptual error that had stymied my previous thinking emerged from joint work with Elisabeth Lloyd, a professional philosopher of science. I take great pride in our two joint articles (Lloyd and Gould, 1993; Gould and Lloyd, 1999) ....

This is a long-winded way of introducing you to Elisabeth Lloyd, a professor in the History and Philosophy of Science and Medicine at Indiana University (Bloomington, Indianna, USA).¹

I just stumbled upon an article written by Elisabeth Lloyd a little over a year ago (Lloyd, 2015). Here's the title and abstract ....

Lloyd, E.A. (2015) Adaptationism and the logic of research questions: how to think clearly about evolutionary causes. Biological Theory, 10:343-362. [doi: 10.1007/s13752-015-0214-2]

This article discusses various dangers that accompany the supposedly benign methods in behavioral evolutionary biology and evolutionary psychology that fall under the framework of “methodological adaptationism.” A “Logic of Research Questions” is proposed that aids in clarifying the reasoning problems that arise due to the framework under critique. The live, and widely practiced, “evolutionary factors” framework is offered as the key comparison and alternative. The article goes beyond the traditional critique of Stephen Jay Gould and Richard C. Lewontin, to present problems such as the disappearance of evidence, the mishandling of the null hypothesis, and failures in scientific reasoning, exemplified by a case from human behavioral ecology. In conclusion the paper shows that “methodological adaptationism” does not deserve its benign reputation.

I realize that most of you won't be able to access this article but for those of you who can, it's well worth reading. As Gould said, sometimes philosophers can clear up conceptual problems. In this case, it's the conceptual problem concerning adaptationism and the proper null hypothesis in evolutionary thinking.

It's been almost 40 years since the publication of the Spandrels paper and yet we still find biologists defending the adaptationist program in its various forms. If you are one of those scientists, read this paper.

Here's her introduction. It shows you what's coming.

We do not usually think that the logic of our scientific methods leads to closed-mindedness, and the inability to see alternatives, or evaluate evidence, but that is exactly what sometimes happens in evolutionary biology of behavioral and morphological traits with one of its most popular methods, despite its benign reputation. In “The Spandrels of San Marco and the Panglossian Paradigm,” Gould and Lewontin (1979) drew attention to several dangers in using this method. In this article, I present a framework for analysis that makes their worries clearer. I also warn of further risks of this methodological framework, expanding on the dangers it poses to scientific reasoning in evolutionary biology. At the same time, I emphasize that I am not attacking the notion of looking for adaptations in evolutionary studies: I am not anti-adaptation. The issues concern which framework is most appropriate and fruitful.

As evolutionary biology is usually taught and conceived, there are a variety of evolutionary forces or types of factors that can influence the form and distribution of a given trait in a population or species (Singh and Krimbas 2000; Futuyma 2013). While natural selection may be the most significant factor, we also have sexual selection, genetic linkage, phyletic history or “inertia,” developmental factors, drift or chance, embryological constraints, and social, environmental, and niche coevolutionary factors (Wright 1931; Odling-Smee et al. 2001; Pigliucci and Müller 2010). Traits can also be byproducts, spandrels, or exaptations of any of these processes in a co-related or linked trait, among other causal and explanatory factors (Gould and Lewontin 1979; Gould and Vrba 1982; Futuyma 2013). Let us call this basic approach the “evolutionary factors” framework of evolutionary theory; its fundamental research question is: “What evolutionary factors account for the form and distribution of this trait?” Often, several of these factors are understood to operate simultaneously on a given trait, but only one or two are the major factors causing its form and distribution at a given time (e.g., Otsuka 2014; see Newman 1988; Amundson 1994, 1998, 2005; Griffiths 1996; Raff 1996; Carroll 2005; Newman and Bhat 2008). When we investigate the evolutionary origins of a given trait, we usually prioritize the functional factors, natural selection and sexual selection, as the most significant factors in evolutionary research, and we might start with the question: “Does this trait have a function?” If the trait, after investigation, does not appear to have a correlation with fitness, or does not appear to have evidence of design (hence, does not appear to have a current or past function), we pursue other possible evolutionary explanations, such as whether it might be due to genetic linkage with another trait, or be an exaptation, or a byproduct of selection (see Gould and Vrba 1982; Gould 2002; Lloyd and Gould ([2002]2014). Alternatively, it may be present due to developmental or embryological constraints, or due to phyletic inertia, and so on (Wake 1991, 2009; Newman and Bhat 2008, 2011; Linde-Medina 2011; Griesemer 2015). Pursuit of such explanations would consist of testing them against available evidence and searching for new evidence specific to those factors, against which they could then be compared.

There is another approach, dominant among leading animal behaviorists, behavioral ecologists, and many human evolutionists and evolutionary psychologists, called “methodological adaptationism.” Under this approach, the leading research question is: “What is the function of this trait?” or “What adaptive explanation can account for this trait?” And the research consists of an exploration and search for supportive evidence for adaptive hypotheses that can explain the trait’s presence in the population.

In case you're in any doubt about her conclusions, let me quote the last paragraph.

I would like to close by again emphasizing that I am not in any way against adaptive explanations themselves. But I have highlighted some risks of a particular very popular approach to research into evolutionary causes. These dangers become obvious when we examine the logic of the research questions and their relevant answers, within the methodological adaptationist approach and the contrasting evolutionary factors framework. When a research method makes any particular types of hypotheses especially difficult to entertain or accept, it deserves serious scrutiny. Keeping the logic of the research questions in mind when dealing with the scientific errors committed by adaptationists allows us to analyze and explain them straightforwardly. The presence of researchers like Symons who engaged in their research using the more inclusive evolutionary factors methodology exemplify a living available alternative method. Evolutionists say that they have learned their lessons about an inclusive approach to evolutionary explanation from Gould and Lewontin’s 1979 “Spandrels” article, but methodological adaptationism seems to make it very difficult for them to act on those lessons.

So, there really are some philosophers who know their stuff! (That doesn't mean the discipline isn't in trouble.)

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1. It just occurred to me that "Indiana" is named after the Indian Territories. I thought it was politically incorrect to appropriate the word "indian" these days?

Gould, S.J., and Lloyd, E.A. (1999) Individuality and adaptation across levels of selection: How shall we name and generalize the unit of Darwinism? Proceedings of the National Academy of Sciences, 96:11904-11909. [doi: 10.1073/pnas.96.21.11904]

Lloyd, E.A., and Gould, S.J. (1993) Species selection on variability. Proceedings of the National Academy of Sciences, 90:595-599. [doi: 10.1073/pnas.90.2.595]