title: Maternal effects and heritability of annual productivity.
abstract: Within-individual consistency and among-individual heterogeneity in fitness are prerequisites for selection to take place. Within-individual variation in productivity between years, however, can vary considerably, especially when organisms become older and more experienced. We examine individual consistency in annual productivity, the covariation between survival and annual productivity, and the sources of variation in annual productivity, while accounting for advancing age, to test the individual-quality and resource-allocation life-history theory hypotheses. We use long-term data from a pedigreed, wild population of house sparrows. Within-individual annual productivity first increased and later decreased with age, but there were no selective mortality due to individual quality and no correlation between lifespan and productivity. Individuals were consistent in their annual productivity (C = 0.49). Narrow-sense heritability was low (h(2) = 0.09), but maternal effects explained much of the variation (M = 0.33). Such effects can influence evolutionary processes and are of major importance for our understanding of how variation in fitness can be maintained.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, UK. julia.schroeder@gmail.com
authors.forename: Julia
authors.initials: J
authors.lastname: Schroeder
authors.forename: T
authors.initials: T
authors.lastname: Burke
authors.forename: M-E
authors.initials: ME
authors.lastname: Mannarelli
authors.forename: D A
authors.initials: DA
authors.lastname: Dawson
authors.forename: S
authors.initials: S
authors.lastname: Nakagawa
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D052284:Clutch Size; D005260:Female; D005298:Fertility; D056084:Genetic Fitness; D008136:Longevity; D008137:Longitudinal Studies; D008297:Male; D008390:Markov Chains; D009010:Monte Carlo Method; D019655:Quantitative Trait, Heritable; D012044:Regression Analysis; D012641:Selection, Genetic; D046370:Sparrows / Q000235:genetics / Q000502:physiology*