Methodologies Order Factors

Methodological adaptationists look for the effects of natural selection on the distribution traits of organisms. This has been critiqued for ignoring the many other causes of trait distributions such as developmental constraints. In Lloyd’s 2015 “Adaptationism and the Logic of Research Questions”, she condemns methodological adaptationism with the logic of research questions framework. In my view, Lloyd’s framework mischaracterizes methodological adaptationism because the framework is impoverished and it unjustly condemns it for being something that it is not.

Lloyd reasons that, because methodological adaptationists ask “What is the function of this trait?”, the only possible answers are “The function of this trait is X.”, ignoring the other evolutionary factors/causes responsible for traits. Instead, she urges all evolutionary biologists to use the evolutionary factors framework and ask, “What evolutionary factors account for this trait?”, to which all evolutionary factors are answers. Indeed, all research programs across the biological sciences should embrace all the relevant factors.

But I do not think methodological positions like adaptationism essentially ignore some causes. Rather they take some causes as their starting point for theorizing, modeling, and explaining. And they do this for good methodological reasons, in part because starting points enable at least two powerful strategies for making progress when you are wrong. To characterize the methodologies of research programs, we need to consider both the factors considered and order considered in. With both of these features, we can describe the methodology that these scientists follow and that they espouse.

To show this, I move to community ecology, one of the most methodologically diverse areas of biology. Lloyd’s recommendation for ecology should be the ecological factors framework, asking “What ecological factors account for the form and distribution of organisms in this community?” Community ecologists generally agree that there are four high-level processes responsible for patterns of abundance and diversity: drift, immigration, speciation, and interspecific competition. Contrast two methodologies:

• Competitionism takes the starting point that all differences between individual differences between species are functional differences and looks first for the effects of interspecific competition/ selection.

• Neutralism takes the starting point that all members in a community are functionally equivalent and looks first for drift, immigration, and speciation.

These programs can be characterized only using both factors considered and order considered in.

Take neutralism, explicitly opposed to competitionism. The basic neutral theory and models includes only drift, immigration, and speciation. Neutralists are not blind to interspecific competition. When neutral models are confronted with data and the model-fit is good, then neutralists invoke drift, immigration, and speciation to explain the data. But when model-fit is bad, neutralists respond with at least one of two strategies:

• Baseline Modeling is used to add additional factors (species differences and competition) to their explanation of the data.

• Adding Complexity is used to relax neutrality and augment the neutral model with the additional factors.

Competitionism also uses both of these strategies.

These programs in community ecology are a problem for Lloyd’s position because the research question framework is too impoverished to both adequately characterize their methodological positions and distinguish them from an ecological factors framework. The proponent of the research question framework faces a dilemma:

(1) Either ecologists should abandon competitionism and neutralism in favor of the ecological factors framework,

(2) Or else these two programs are not analogs of methodological adaptationism but of the ecological factors framework.

Response (1) is unacceptable because these are successful programs that persist against calls for unity within ecology. Response (2) mischaracterizes the situation because competitionism and neutralism are both clearly distinct from each other, and from other programs lacking a starting point.

In order to characterize such methodological positions, we need to include both the factors considered and the order considered in. In ecology, we have Drift, Immigration, Speciation, and Competition. Let {}-brackets mark unordered sets and ()-brackets ordered sequences. Lloyd’s framework would mischaracterize competitionism, neutralism, and the ecological factors framework as:

{C} {D, I, S} {D, I, S, C}

Instead, considering both factors and order, we get:

(C, {D, I, S}) ({D, I, S}, C) {D, I, S, C}

This enables us to both recognize and analyze the diversity of methodologies across biology.

Adaptationism and analogous methodologies consider their preferred factor first. While some adaptationist programs have dogmatically failed to look beyond their starting point, this is not an essential feature of adaptationism and its analogs. Instead, these positions take a methodological starting point that enables powerful strategies such as Baseline Modeling and Adding Complexity to give direction to their further research when something goes wrong.