Scaffolds and scaffolding: an explanatory strategy in evolutionary biology

Abstract

In recent years, the explanatory term “scaffold” has been gaining prominence in evolutionary biology. This notion has a long history in other areas, in particular, developmental psychology. In this paper, we connect these two traditions and identify a specific type of explanatory strategy shared between them, namely scaffolding explanations. We offer a new definition of “scaffold” anchored in the explanatory practices of evolutionary biologists and developmental psychologists that has yet to be clearly articulated. We conclude by offering a systematic overview of the various dimensions of scaffolding explanations that further suggests both their usefulness and range of application.

Scaffold: A Causal Concept for Evolutionary Explanations

“…As we have argued elsewhere (Jones et al 2023;Neto et al 2023), the work of Rainey and collaborators illustrates the general features of evolutionary scaffolds.…”

“…Instead of focusing solely on the genetic composition and mechanisms internal to cells, Rainey and his collaborators indicate how changes in the environmental conditions could create a scaffold that produces and sustains a population-level selection process that results in the origin of cooperation. As we discuss in the following text, this exemplifies what we call "evolutionary scaffolding explanations" (Neto et al 2023).…”

“…Indeed, one might suspect that when scientists use “scaffold” they are simply employing a suggestive metaphor that amounts to nothing more than a synonym for “cause” or “interactive phenomena” (Charbonneau 2015). In this article, we expand on our previous work and present evolutionary scaffolding explanation as a distinct type of explanatory strategy, distinguishing it from other types of causal explanation in evolutionary biology (Jones et al 2023; Neto et al 2023). By doing so, we clarify the meaning of “scaffold” as a causal concept and its relevance in evolutionary explanations.…”

“…Scaffolds are causes in the sense of difference-makers, something that can be expressed using counterfactual and interventionist accounts of causation (Woodward 2003). But more than this, they interact over time with a system (i.e., a population) to both create and sustain the outcome of interest (Neto et al 2023). No mere trigger, if scaffolds are removed too early, this process will end, and the outcome of interest will not be realized.…”

“…These strategies differ in terms of focus (population or other nonpopulational focus), process driver (internal vs. external), causal robustness (robust-process vs. actual sequence), and causal character (stochastic/statistical, mechanistic, or dispositional). Second, relying on previous work, we define “scaffold” and describe how scaffolding processes figure in explanations of evolutionary transitions (Neto et al 2023). In so doing, we show that such explanations are distinct from the strategies previously surveyed.…”