Data from: Reduced fitness in progeny from old parents in a natural population

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.

已有研究在实验室条件下的多个动物类群（taxa）中，报道了亲本年龄对后代适合度（offspring fitness）的非遗传跨代效应。这类跨代适合度效应，将对种群动态、种群年龄结构以及衰老与寿命的演化产生重要影响。然而，此前尚未在自然种群中证实亲本年龄对后代终生适合度的影响。本研究基于野生家麻雀的岛屿谱系种群（pedigreed insular population）数据，证实亲本年龄对后代终生适合度存在性别特异性的负面影响。亲本年龄较大的个体，其每年产生的招募个体（recruits）数量低于亲本年龄较小的个体，而招募个体数量的减少最终带来了终生适合度的差异。通过长期交叉抚育实验（cross-fostering experiment），本研究证实该亲本年龄效应不太可能由环境变化所致，而是可能通过表观遗传（epigenetic）方式传递。本研究揭示了晚龄繁殖所带来的、可延续至下一代的隐性后果。