Reznick David, Ghalambor Cameron, Nunney Leonard
Department of Biology, University of California, Riverside, CA 92521, USA.
Mech Ageing Dev. 2002 Apr;123(7):773-89. doi: 10.1016/s0047-6374(01)00423-7.
Fish are over-represented among the vertebrates that are known to live over 100 years. Such trends in maximum longevity suggest that fish also experience delayed senescence relative to other vertebrates. Most applications of evolutionary theory suggest that the extrinsic mortality rate, or mortality that is attributable to external factors like disease or predation, is the major factor that shapes the evolution of senescence, so that the only way to evolve delayed senescence is to experience lower rates of extrinsic mortality. We propose instead that fish are more inclined to evolve delayed senescence because they have indeterminate growth and, as a consequence, have the capacity for a substantial increase in fecundity with age. It is thus the combined effects of the expectation of survival and fecundity that shape the evolution of senescence, as originally proposed by Williams (1957). We also argue that fish share many of the same general mechanisms that shape the evolution of senescence in other vertebrates. We support this argument with statistical analyses of life history data that show the same patterns of correlation among traits as seen in birds and mammals.
在已知能活到100岁以上的脊椎动物中，鱼类所占比例过高。这种最大寿命的趋势表明，相对于其他脊椎动物，鱼类也经历了衰老延迟。进化理论的大多数应用表明，外在死亡率，即归因于疾病或捕食等外部因素的死亡率，是塑造衰老进化的主要因素，因此进化出延迟衰老的唯一途径是经历较低的外在死亡率。相反，我们认为鱼类更倾向于进化出延迟衰老，因为它们具有无限生长的特性，因此有能力随着年龄的增长而大幅提高繁殖力。因此，正如威廉姆斯（1957年）最初提出的那样，塑造衰老进化的是生存期望和繁殖力的综合作用。我们还认为，鱼类与其他脊椎动物一样，拥有许多塑造衰老进化的一般机制。我们通过对生活史数据的统计分析来支持这一观点，这些分析表明，鱼类的性状之间存在与鸟类和哺乳动物相同的相关模式。
