Centre for Biodiversity Dynamics (CBD), Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland.
Ecol Lett. 2021 Oct;24(10):2077-2087. doi: 10.1111/ele.13835. Epub 2021 Jul 26.
Generation time determines the pace of key demographic and evolutionary processes. Quantified as the weighted mean age at reproduction, it can be studied as a life-history trait that varies within and among populations and may evolve in response to ecological conditions. We combined quantitative genetic analyses with age- and density-dependent models to study generation time variation in a bird metapopulation. Generation time was heritable, and males had longer generation times than females. Individuals with longer generation times had greater lifetime reproductive success but not a higher expected population growth rate. Density regulation acted on recruit production, suggesting that longer generation times should be favoured when populations are closer to carrying capacity. Furthermore, generation times were shorter when populations were growing and longer when populations were closer to equilibrium or declining. These results support classic theory predicting that density regulation is an important driver of the pace of life-history strategies.
世代时间决定了关键人口和进化过程的速度。它可以被量化为繁殖时的加权平均年龄，作为一种在种群内和种群间变化的生活史特征，可能会对生态条件做出反应而进化。我们结合定量遗传分析和年龄和密度依赖模型来研究鸟类复合种群的世代时间变化。世代时间是可遗传的，雄性的世代时间比雌性长。具有较长世代时间的个体具有更大的终生繁殖成功率，但没有更高的预期种群增长率。密度调节作用于繁殖体的产生，这表明当种群接近承载能力时，较长的世代时间应该是有利的。此外，当种群增长时，世代时间较短，而当种群更接近平衡或下降时，世代时间较长。这些结果支持了经典理论，即密度调节是生活史策略速度的重要驱动因素。
