Abstract The extinction of RNA virus populations upon application of a mutagenic drug is frequently referred to as evidence for the existence of an error threshold, above which the population cannot sustain the mutational load. To explain the extinction process after reaching this threshold, models of lethal mutagenesis have been proposed, in which extinction is described as a deterministic (and thus population size-independent) process. As a separate body of literature, the population genetics community has developed models of mutational meltdown, which focus on the stochastic (and thus population-size dependent) processes governing extinction. However, recent extensions of both models have blurred these boundaries. Here, we first clarify definitions in terms of assumptions, expectations, and relevant parameter spaces, and then assess similarities and differences. As concepts from both fields converge, we argue for a unified theoretical framework that is focused on the evolutionary processes at play, rather than dispute over terminology.

中文翻译：

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同一枚硬币的两个方面：关于致死突变和突变崩溃的种群遗传学观点

摘要 应用诱变药物后 RNA 病毒种群的灭绝通常被称为错误阈值存在的证据，高于该阈值的种群不能承受突变负荷。为了解释达到这个阈值后的灭绝过程，有人提出了致死突变模型，其中灭绝被描述为一个确定性的（因此与种群大小无关）过程。作为单独的文献体系，种群遗传学界已经开发了突变崩溃模型，该模型侧重于控制灭绝的随机（因此取决于种群规模）过程。然而，这两种模型最近的扩展已经模糊了这些界限。在这里，我们首先在假设、期望和相关参数空间方面澄清定义，然后评估相同点和不同点。随着来自两个领域的概念的融合，我们主张建立一个统一的理论框架，该框架侧重于正在发挥作用的进化过程，而不是对术语的争论。