Recurrent violations of invariant rules for offspring size: evidence from turtles and the implications for small clutch size models

摘要: Smith and Fretwell’s classic model predicts that parents can maximize fitness by dividing the energy available for reproduction into offspring of an optimal size. However, this breaks down when clutch size is small (~1–10 offspring). Invariant rules are extension Smith–Fretwell model, these predict how will vary among within individuals produce sizes. Here, we provide a narrow test invariant using three turtle species, then synthesize re-analyze existing data from 18 different species (comprising five Orders) to evaluate whether followed across broad taxa. We do not find support most in turtles, our re-analysis demonstrates general mismatch between observed expected values all taxa evaluated, suggesting fail reproductive patterns nature. Morphological constraints on effort may be important reasons disparities theory observation both turtles other Paradoxically, morphological common small-bodied individuals, but same candidates also those which sizes necessary rules, such fair often challenging. Mismatches might occur because assumes mothers exert control over resource allocation offspring. In fact, there evidence widespread genetic correlations investment per effort, traits independent.