Ferrière R, Gatto M
Laboratoire d'Ecologie, Ecole Normale Supérieure, Paris, France.
Proc Biol Sci. 1993 Jan 22;251(1330):33-8. doi: 10.1098/rspb.1993.0005.
The question of whether animal populations display chaotic dynamics has motivated a thriving body of research for two decades. Yet unambiguous evidence for chaos in the wild remains scarce. Accordingly, it has been proposed that evolutionary forces act to preserve populations from chaos as well as oscillations. We have tested for this hypothesis by considering the dynamics associated with evolutionarily stable life histories (including age of maturity, adult survivorship and recruitment to adulthood) in a simple, but general, demographic model. Contrary to expectation, individual selection operating on demographic traits should often lead to oscillatory or chaotic dynamics for species with late feasible ages of maturity and many age classes. Also, the optimality of chaos is more likely whenever trade-offs constrain recruitment to rapidly decrease with increasing adult survival or decreasing age of maturity. Our results bring evolutionary support to the possibility that chaotic population dynamics might be much more widespread than inferred until now from data analyses. Furthermore, these findings provide novel support for the view that chaos could be an optimal regime for several biological systems.
二十年来，动物种群是否呈现混沌动态这一问题推动了大量研究的蓬勃发展。然而，野外混沌的确切证据仍然稀少。因此，有人提出进化力量会促使种群避免出现混沌以及振荡。我们通过在一个简单但通用的种群统计学模型中考虑与进化稳定生活史（包括成熟年龄、成年个体存活率和成年个体补充率）相关的动态变化，对这一假设进行了检验。与预期相反，对于成熟年龄可行期较晚且年龄组众多的物种，作用于种群统计学特征的个体选择往往会导致振荡或混沌动态。此外，只要权衡取舍限制了补充率随着成年个体存活率的增加或成熟年龄的降低而迅速下降，混沌的最优性就更有可能出现。我们的结果为混沌种群动态可能比目前从数据分析中推断的更为普遍这一可能性提供了进化方面的支持。此外，这些发现为混沌可能是若干生物系统的最优状态这一观点提供了新的支持。
