Senescence—the decline in age‐specific contribution to fitness with increasing age—has been widely investigated in evolutionary ecology. A tremendous amount of detailed empirical analyses have now revealed the widespread occurrence of demographic senescence (i.e. both actuarial and reproductive senescence) and have started to identify factors (e.g. environmental conditions) that modulate its timing and intensity, both within and across species. In this special feature, we have built on this flourishing work to highlight several axes of research that would benefit from more integrative and multidisciplinary approaches. Several contributions compiled in this special feature emphasize that our understanding of senescence remains taxonomically limited, mostly focused on birds and mammals, and is therefore not representative of the biological diversity displayed across the tree of life. In line with this observation, the influence of some peculiar lifestyles (e.g. involving sociality or modularity) on the evolution of senescence is yet to be deciphered. Understanding of the diversity of senescence patterns across and within species and among traits will necessitate the establishment of new metrics as a golden standard to fully account for age‐specific changes recorded in individuals’ performance. This is illustrated with the specific case of actuarial senescence. This special feature also highlights that the diversity of biological samples collected from wild plants and animals, along with accurate demographic data, is expanding. The fast development of new molecular tools now offers a unique opportunity to launch research programmes at the interface of physiology, health and ageing in non‐model organisms. We argue that while these different research axes constitute key avenues of investigations for the coming years, they are only the tip of the iceberg. To appreciate the full complexity of the senescence process in nature, from its evolutionary causes to its demographic consequences, we also need a better understanding of the role played by both environmental conditions and gene–environment interactions, of constraints, and of senescence, an improved assessment of the influence of individual heterogeneity, and the consideration of transgenerational effects when quantifying the fitness consequences of senescence.

中文翻译：

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自然衰老的综合观点

衰老——随着年龄的增长对健康的特定年龄贡献的下降——已在进化生态学中得到广泛研究。大量详细的实证分析现已揭示人口衰老（即精算衰老和生殖衰老）的广泛发生，并已开始确定在物种内和物种间调节其时间和强度的因素（例如环境条件）。在这个特殊的专题中，我们在这项蓬勃发展的工作的基础上突出了几个研究轴，这些轴将受益于更综合和多学科的方法。本专题中汇编的几篇文章强调，我们对衰老的理解在分类学上仍然有限，主要集中在鸟类和哺乳动物上，因此不能代表整个生命之树所展示的生物多样性。根据这一观察，一些特殊的生活方式（例如，涉及社会性或模块化）对衰老进化的影响尚待破译。了解物种之间和内部以及性状之间衰老模式的多样性将需要建立新的指标作为黄金标准，以充分考虑个体表现中记录的特定年龄变化。精算衰老的具体案例说明了这一点。这一特殊功能还突出表明，从野生动植物中收集的生物样本的多样性以及准确的人口统计数据正在扩大。新分子工具的快速发展现在为在非模式生物的生理、健康和衰老的界面上启动研究计划提供了独特的机会。我们认为，虽然这些不同的研究轴构成了未来几年研究的关键途径，但它们只是冰山一角。为了理解自然界衰老过程的全部复杂性，从其进化原因到其人口统计学后果，我们还需要更好地了解环境条件和基因 - 环境相互作用、约束和衰老所发挥的作用，一个改进的评估个体异质性的影响，并在量化衰老的健康后果时考虑跨代效应。非模式生物的健康和衰老。我们认为，虽然这些不同的研究轴构成了未来几年研究的关键途径，但它们只是冰山一角。为了理解自然界衰老过程的全部复杂性，从其进化原因到其人口统计学后果，我们还需要更好地了解环境条件和基因 - 环境相互作用、约束和衰老所发挥的作用，一个改进的评估个体异质性的影响，并在量化衰老的健康后果时考虑跨代效应。非模式生物的健康和衰老。我们认为，虽然这些不同的研究轴构成了未来几年研究的关键途径，但它们只是冰山一角。为了理解自然界衰老过程的全部复杂性，从其进化原因到其人口统计学后果，我们还需要更好地了解环境条件和基因 - 环境相互作用、约束和衰老所发挥的作用，一个改进的评估个体异质性的影响，并在量化衰老的健康后果时考虑跨代效应。