Syngenta, Jealott's Hill International Research Centre , Bracknell RG42 6EY, UK.
Living Systems Institute, University of Exeter , Exeter EX4 4PY, UK.
Proc Biol Sci. 2024 Jun;291(2025):20240805. doi: 10.1098/rspb.2024.0805. Epub 2024 Jun 26.
Evolutionary rescue occurs when the genetic evolution of adaptation saves a population from decline or extinction after environmental change. The evolution of resistance to pesticides is a special scenario of abrupt environmental change, where rescue occurs under (very) strong selection for one or a few de novo resistance mutations of large effect. Here, a population genetic model of evolutionary rescue with density-dependent population change is developed, with a focus on deriving results that are important to resistance management. Massive stochastic simulations are used to generate observations, which are accurately predicted using analytical approximations. Key results include the probability density function for the time to resistance and the probability of population extinction. The distribution of resistance times shows a lag period, a narrow peak and a long tail. Surprisingly, the mean time to resistance can increase with the strength of selection because, if a mutation does not occur early on, then its emergence is delayed by the pesticide reducing the population size. The probability of population extinction shows a sharp transition, in that when extinction is possible, it is also highly likely. Consequently, population suppression and (local) eradication can be theoretically achievable goals, as novel strategies to delay resistance evolution.
当遗传适应性进化在环境变化后拯救种群免于衰退或灭绝时，就会发生进化拯救。抗药性的进化是一个特殊的环境急剧变化的情况，在这种情况下，由于对一个或几个具有大效应的新出现的抗药性突变的强烈选择，会发生拯救。在这里，开发了一个具有密度依赖性种群变化的进化拯救的种群遗传模型，重点是得出对抗性管理很重要的结果。使用大规模随机模拟生成观测结果，并使用分析近似值准确预测。主要结果包括抗药性时间的概率密度函数和种群灭绝的概率。抗药性时间的分布显示出滞后期、窄峰和长尾。令人惊讶的是，抗药性时间的平均值可以随着选择强度的增加而增加，因为如果突变早期不发生，那么由于杀虫剂降低了种群规模，它的出现就会被延迟。种群灭绝的概率显示出急剧的转变，即当灭绝是可能的时候，它也极有可能发生。因此，种群抑制和（局部）根除可以作为延迟抗药性进化的新策略，从理论上实现目标。
