title: Reduced fitness in progeny from old parents in a natural population.
abstract: A nongenetic, transgenerational effect of parental age on offspring fitness has been described in many taxa in the laboratory. Such a transgenerational fitness effect will have important influences on population dynamics, population age structure, and the evolution of aging and lifespan. However, effects of parental age on offspring lifetime fitness have never been demonstrated in a natural population. We show that parental age has sex-specific negative effects on lifetime fitness, using data from a pedigreed insular population of wild house sparrows. Birds whose parents were older produced fewer recruits annually than birds with younger parents, and the reduced number of recruits translated into a lifetime fitness difference. Using a long-term cross-fostering experiment, we demonstrate that this parental age effect is unlikely to be the result of changes in the environment but that it potentially is epigenetically inherited. Our study reveals the hidden consequences of late-life reproduction that persist into the next generation.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom; Evolutionary Biology, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany; and julia.schroeder@gmail.com.
authors.forename: Julia
authors.initials: J
authors.lastname: Schroeder
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom; Department of Zoology, University of Otago, Dunedin 9054, New Zealand.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom;
authors.forename: Mark
authors.initials: M
authors.lastname: Rees
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom;
authors.forename: Maria-Elena
authors.initials: ME
authors.lastname: Mannarelli
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom;
authors.forename: Terry
authors.initials: T
authors.lastname: Burke
mesh_terms: D000367:Age Factors; D000818:Animals; D005075:Biological Evolution; D004777:Environment; D044127:Epigenesis, Genetic; D005260:Female; D056084:Genetic Fitness; D008297:Male; D015233:Models, Statistical; D011157:Population Dynamics; D012098:Reproduction; D046370:Sparrows / Q000502:physiology*
keywords: aging; epigenetic; indirect effects; senescence; transgenerational