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Abstract Variation of form–function relationships within populations is the substrate for adaptation at higher levels. Therefore, assessing similarity in form–function relationships within and between species may help reveal the processes shaping functional diversity. Here, we test such similarity across three levels of anuran phenotypic divergence: within a population, among species in a single family (Hylidae; ~60 myr), and across a much broader sample of all anuran species using a single microhabitat (arboreal; ~120 myr). We expected less interspecific divergence to show higher similarity of form–function relationships with the intraspecific level. We analyzed the relationships between locomotor performance (in both swimming and jumping) and several hindlimb traits across these three evolutionary levels. While we found a positive correlation between swimming and jumping velocity at both intra- and interspecific levels, relationships between performance and body form did not match across levels. We suggest that different strengths of functional constraints or trade-offs may have produced more variation in form–function relationships across species, decoupling them from within-species patterns. We conclude that performance landscapes are likely qualitatively different across the different evolutionary scales, potentially reflecting changes in the relative importance of different behaviors across all arboreal species. 

Evolution by natural selection and adaptation are core concepts in biology that students must see and correctly understand their meaning. However, using these concepts in evidence-based learning strategies in the classroom is a difficult task. Here, we present a 5E lesson plan to address the Next Generation Science Standards performance expectation HS-LS4-4, to “construct an explanation based on evidence for how natural selection leads to adaptation of populations.” The Functional Frogs lesson provides multiple hands-on activities to engage students in the development of hypotheses, collection and analysis of empirical data on frog swimming, presentation of results, and construction of explanations supported by evidence for the results. The lesson’s central idea is for students to understand the trait values that provide an advantage in the aquatic environment, increasing a frog’s survival. The link between morphological changes and survival is used to explain how natural selection acts on populations, leading to adaptive evolution.