Diversity of ageing across the tree of life

摘要

Evolution drives, and is driven by, demography. A genotype moulds its phenotype's age patterns of mortality and fertility in an environment; these two patterns in turn determine the genotype's fitness in that environment. Hence, to understand the evolution of ageing, age patterns of mortality and reproduction need to be compared for species across the tree of life. However, few studies have done so and only for a limited range of taxa. Here we contrast standardized patterns over age for 11 mammals, 12 other vertebrates, 10 invertebrates, 12 vascular plants and a green alga. Although it has been predicted that evolution should inevitably lead to increasing mortality and declining fertility with age after maturity, there is great variation among these species, including increasing, constant, decreasing, humped and bowed trajectories for both long- and short-lived species. This diversity challenges theoreticians to develop broader perspectives on the evolution of ageing and empiricists to study the demography of more species.%人们通常假设，衰老伴随着生殖率降低和死亡率增加。但正如Owen Jones等人在对各种不同动物和植物的生命史模式所做的这一涉及面非常广的调查中所发现的那样，这种假设也许是狭隘的。原来，死亡率和生殖率在短寿和长寿物种中随年龄增长都有巨大变化，并没有适合所有情形的单一模式。衰老、死亡和生殖之间的关系显然是复杂的，还需要更多的工作来获得更全面的认识。理论工作者需要建立能更充分反映衰老的多样性的模型，同时对更多样化的物种进行实验也会是有用的。