Am Nat. 2024 Aug;204(2):E28-E41. doi: 10.1086/730446. Epub 2024 Jun 14.
AbstractIndividual variability in mortality is widespread in nature. The general rule is that larger organisms have a greater chance of survival than smaller conspecifics. There is growing evidence that differential mortality between developmental stages has important consequences for the ecology and evolution of populations and communities. However, we know little about how it can influence diversification. Using an eco-evolutionary model of diversification that considers individual variability in mortality, I show that commonly observed differences in mortality between juveniles and adults can facilitate adaptive diversification. In particular, diversification is expected to be less restricted when mortality is more biased toward juveniles. Additionally, I find stage-specific differences in metabolic cost and foraging capacity to further facilitate diversification when adults are slightly superior competitors, due to either a lower metabolic cost or a higher foraging capacity, than juveniles. This is because by altering the population composition, differential stage-specific mortality and competitive ability can modulate the strength of intraspecific competition, which in turn determines the outcome of diversification. These results demonstrate the strong influence that ecological differences between developmental stages have on diversification and highlight the need for integrating developmental processes into diversification theory.
摘要：个体间的死亡率差异在自然界中非常普遍。一般来说，较大的生物体比同种的较小个体有更大的生存机会。越来越多的证据表明，不同发育阶段的死亡率差异对种群和群落的生态和进化有重要影响。然而，我们对它如何影响多样化知之甚少。利用一个考虑死亡率个体差异的生态进化多样化模型，我表明，在青少年和成年人之间常见的死亡率差异可以促进适应性多样化。特别是，当死亡率更偏向于青少年时，多样化的限制预计会更小。此外，我发现当成年人比青少年具有更低的代谢成本或更高的觅食能力时，代谢成本和觅食能力的特定阶段差异进一步促进了多样化，因为它们是稍微优秀的竞争者。这是因为通过改变种群组成，特定阶段的死亡率和竞争能力的差异可以调节种内竞争的强度，而种内竞争的强度又决定了多样化的结果。这些结果表明，发育阶段之间的生态差异对多样化有很强的影响，并强调需要将发育过程纳入多样化理论。
