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类群（taxa）中，报道了亲本年龄对后代适合度（offspring fitness）的非遗传性跨代效应。此类跨代适合度效应，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，亲本年龄对后代终身适合度（lifetime fitness）的效应，迄今尚未在自然种群中得到证实。本研究依托野生家麻雀的谱系岛屿种群数据，揭示了亲本年龄对后代终身适合度存在性别特异性的负向影响。亲本年龄较高的个体，其每年产生的补充个体（recruits）数量，相较于亲本年龄较低的个体更少；而补充个体数量的缩减，最终转化为终身适合度的差异。通过长期交叉抚育（cross-fostering）实验，我们证实该亲本年龄效应不太可能由环境变化所致，而是极有可能经由表观遗传机制进行传递。本研究揭示了晚育行为所带来的、可延续至下一代的隐性后果。