Programmed life span in the context of evolvability

Population turnover is necessary for progressive evolution. In the context of a niche with fixed carrying capacity, aging contributes to the rate of population turnover. Theoretically, a population in which death is programmed on a fixed schedule can evolve more rapidly than one in which population turnover is left to a random death rate. Could aging evolve on this basis? Quantitative realization of this idea is problematic, since the short-term individual fitness cost is likely to eliminate any hypothetical gene for programmed death before the long-term benefit can be realized. In 2011, one of us proposed the first quantitative model based on this mechanism that robustly evolves a finite, programmed life span. That model was based on a viscous population in a rapidly changing environment. Here, we strip this model to its essence and eliminate the assumption of environmental change. We conclude that there is no obvious way in which this model is unrealistic, and that it may indeed captu...种群更新（population turnover）对于渐进式演化而言是必不可少的。在生态位（niche）环境容纳量固定的情境下，衰老会提升种群更新的速率。从理论上来说，死亡按照固定程序发生的种群，其演化速率要快于种群更新仅依赖随机死亡率的种群。那么衰老能否基于这一机制完成演化？但该假说的量化实现存在难题：因为在长期收益得以显现前，短期的个体适合度成本（fitness cost）大概率会清除任何假想的程序性死亡相关基因。2011年，本文作者之一提出了首个基于该机制的量化模型，该模型可稳定演化出有限且程序化的寿命。该模型基于快速变化环境中的粘性种群（viscous population）构建。本文中，我们将该模型提炼至其核心本质，并移除了环境变化的假设前提。我们的研究结论为：该模型并无明显的非现实之处，其或确实能够捕捉...