Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Sci Rep. 2017 Mar 6;7:43966. doi: 10.1038/srep43966.
Biodiversity has long been a source of wonder and scientific curiosity. Theoretically, the co-occurrence of competitive species requires niche differentiation, and such differences are well known; however, the neutral theory, which assumes the equivalence of all individuals regardless of the species in a biological community, has successfully recreated observed patterns of biodiversity. In this research, the evolution of sex allocation is demonstrated to be the key to resolving why the neutral theory works well, despite the observed species differences. The sex allocation theory predicts that female-biased allocation evolves in species in declining density and that this allocation improves population growth, which should lead to an increase in density. In contrast, when the density increases, a less biased allocation evolves, which reduces the population growth rate and leads to decreased density. Thus, sex allocation provides a buffer against species differences in population growth. A model incorporating this mechanism demonstrates that hundreds of species can co-occur over 10,000 generations, even in homogeneous environments, and reproduces the observed patterns of biodiversity. This study reveals the importance of evolutionary processes within species for the sustainability of biodiversity. Integrating the entire biological process, from genes to community, will open a new era of ecology.
生物多样性长期以来一直是人们惊叹和科学探究的源泉。从理论上讲，竞争物种的共存需要生态位分化，而这种差异是众所周知的；然而，中性理论假设生物群落中所有个体的等同性，而不论其属于哪个物种，它成功地再现了观察到的生物多样性模式。在这项研究中，性分配的进化被证明是解决为什么中性理论尽管观察到了物种差异，但仍能很好地发挥作用的关键。性分配理论预测，在密度下降的物种中，雌性偏向的分配会进化，而这种分配会改善种群增长，从而导致密度增加。相反，当密度增加时，分配的偏向性会减少，从而降低种群增长率并导致密度降低。因此，性分配为种群增长的物种差异提供了缓冲。一个包含这种机制的模型表明，即使在同质环境中，数百个物种也可以共存超过 10000 代，并再现了观察到的生物多样性模式。这项研究揭示了物种内进化过程对生物多样性可持续性的重要性。将从基因到群落的整个生物过程整合起来，将开创生态学的新纪元。
