MULLERS RATCHET AND MUTATIONAL MELTDOWNS
MULLERS RATCHET AND MUTATIONAL MELTDOWNS
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DOI：
10.1111/j.1558-5646.1993.tb01266.x
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发表时间：
1993-12-01
期刊：
影响因子：
3.3
通讯作者：
BURGER, R
中科院分区：
文献类型：
--
作者：
GABRIEL, W;LYNCH, M;BURGER, R
我们扩展了我们以前的工作中的作用，有害的突变灭绝的专性无性种群。首先，我们开发了突变累积的分析模型，该模型在参数空间的某些范围内消除了耗时的计算机模拟的需要。当每一代进入种群的突变数量相当高时，可以使用数量遗传学中的经典方法预测每个个体的突变数量和平均灭绝时间。然而，当突变率非常低时，固定概率方法是非常有效的。其次，我们证明了一个中间选择系数（s）最小化灭绝时间。s的临界值可以是相当低的，我们讨论了这一点的进化意义，表明增加敏感性突变和DNA修复能力的丧失可以选择性地在无性生物中是有利的。最后，我们考虑的后果的突变融化的线粒体谱系的灭绝性物种。
We extend our earlier work on the role of deleterious mutations in the extinction of obligately asexual populations. First, we develop analytical models for mutation accumulation that obviate the need for time-consuming computer simulations in certain ranges of the parameter space. When the number of mutations entering the population each generation is fairly high, the number of mutations per individual and the mean time to extinction can be predicted using classical approaches in quantitative genetics. However, when the mutation rate is very low, a fixation-probability approach is quite effective. Second, we show that an intermediate selection coefficient (s) minimizes the time to extinction. The critical value of s can be quite low, and we discuss the evolutionary implications of this, showing that increased sensitivity to mutation and loss of capacity for DNA repair can be selectively advantageous in asexual organisms. Finally, we consider the consequences of the mutational meltdown for the extinction of mitochondrial lineages in sexual species.