Testing for equality of evolutionary rates.
Testing for equality of evolutionary rates.
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作者：
S. Muse;B. Weir
提出了一种似然比检验，用于比较通向两个物种的进化路径的进化变化率。这项测试与以前的基于碱基替换估计数量的方差的相对率测试进行了比较。似然方法允许不同的平移和转换率，当这些比率实际上不同时，似然比检验可能比基于方差的检验更强大。然而，对于单参数突变模型，这两个检验具有类似的威力。这些测试应用于几种禾本科植物的一组叶绿体序列，并通过似然比测试发现了导致大麦速率显著不同的其他迹象。
A likelihood ratio test is presented for comparing rates of evolutionary change in the paths of descent leading to two species. The test is compared to previous relative rate tests based on variances of estimated numbers of base substitutions. The likelihood approach allows for different transversion and transition rates, and when these rates are actually different, the likelihood ratio test can be much more powerful than the variance-based tests. For single-parameter mutation models, however, the two tests have similar power. The tests are applied to a set of chloroplast sequences from several species of grasses, and additional indications of significantly different rates leading to barley were found with the likelihood ratio test.