期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：13
页码：4021-4025
DOI：10.1073/pnas.1422715112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceAs parents age, gamete quality declines. If this decline affects the next generation, it could influence the evolution of longevity. Older parents often produce offspring of low fitness in the laboratory. Our long-term data from a natural bird population shows, for the first time to our knowledge, a transgenerational reduction in fitness of the next generation associated with parental age. We use a 10-year cross-fostering experiment to exclude environmental explanations. Our results challenge the currently favored hypothesis in evolutionary biology and behavioral ecology that old age signals high quality in mating partners. Our results imply a substantial cost of reproducing with older, rather than younger, partners. The results inform increasing concern about delayed reproduction in medicine, sociology, and conservation biology. 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.
