Integrating Behavior in Life-History Theory: Allocation versus Acquisition?

Current theory predicts that among-individual variation in behavior is maintained by how individuals resolve life-history trade-offs. Individuals exhibit 'fast' phenotypes are expected to allocate more into current reproduction and acquire resources fuel this investment, whereas 'slow' phenotypes, have lower acquisition, predicted future reproduction. Thus, assumes the simultaneous presence of behaviorally mediated both resource allocation acquisition. We highlight explicit considerations whether closely linked variance acquisition or can improve predictions about observed correlations between traits, draw general implications for theory. Central theories explaining maintenance individual differences build on assumption mediates trade-offs However, empirical evidence does not robustly support assumption. This mismatch might be because clear role versus resources, hindering testing. The relative importance compared a key feature classic theory, but appears been lost translation recent developments involving behavior. argue determining balance process, will help robust precise predictions. collection consumption from environment. division two physiological processes within an individual. labile trait, example behavior, sample caused their average trait expression (measured across multiple observations). combination additive genetic effects (permanent) environment phenotypes. level differs phenotypic (see following text) residual included. varies hierarchical levels biological organization. For example, behavioral vary among observations (within individuals), individuals, genotypes, populations, species. correlated suite traits typically characterized fast growth, quicker time maturity, shorter lifespan. These also express relatively high activity, boldness, exploration, aggression, higher metabolic rates. expressed population has partitioned contributing components. include influence genetic, permanent environmental, and/or expression. slower delayed maturation, longer low constraint (i.e., intraindividual) processes. limited 'competing' may underpin investment (e.g., offspring) growth)