Starting with pattern, focusing on novelty (The “Explainer”)

Theory can be motivated as providing a novel mechanism to explain a particular pattern. In this role, one could frame a question like ‘Here is a pattern, can – and under what conditions does – this mechanism generate it?’ For example, the pattern of species coexistence is often viewed from a lens of competitive interactions between species [21]. A recent paper by McPeek et al. [22] explored how the mechanism of mutualistic relationships could foster coexistence between competitors by asking, ‘Under what conditions can mutualistic relationships between two competitors lead to their coexistence?’ As a second example, consider the observed pattern that some spreading populations fluctuate in how fast they spread over time, expanding quickly in some years and expanding slowly (or even contracting) in others. This pattern is often attributed to environmental heterogeneity or stochasticity [23,24]. Sullivan et al. [25] developed a model to show how the mechanism of deterministic internal population dynamics alone could generate fluctuations in spreading speed, by asking, ‘under what conditions can fluctuations occur in deterministic models with spatially and temporally constant environments?’