Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA.
Evolution. 2012 May;66(5):1413-29. doi: 10.1111/j.1558-5646.2011.01542.x. Epub 2012 Jan 23.
Species as evolutionary lineages are expected to show greater evolutionary independence from one another than are populations within species. Two measures of evolutionary independence that stem from the study of isolation-with-migration models, one reflecting the amount of gene exchange and one reflecting the time of separation, were drawn from the literature for a large number of pairs of closely related species and pairs of populations within species. Both measures, for gene flow and time, showed broadly overlapping distributions for pairs of species and for pairs of populations within species. Species on average show more time and less gene flow than populations, but the similarity of the distributions argues against there being a qualitative difference associated with species status, as compared to populations. The two measures of evolutionary independence were similarly correlated with F(ST) estimates, which in turn also showed similar distributions for species comparisons relative to population comparisons. The measures of gene flow and separation time were examined for the capacity to discriminate intraspecific differences from interspecific differences. If used together, the two measures could be used to develop an objective (in the sense of being repeatable) measure for species diagnosis.
物种作为进化谱系，彼此之间应该表现出比物种内的种群更大的进化独立性。从隔离与迁移模型的研究中得出了两个衡量进化独立性的指标，一个反映基因交换的程度，另一个反映分离的时间，这些指标被用于大量的近缘物种对和物种内的种群对。对于基因流动和时间，这两个指标在物种对和物种内种群对之间都有广泛重叠的分布。物种平均比种群显示出更多的时间和更少的基因流动，但分布的相似性表明，与种群相比，物种状态并没有与之相关的定性差异。这两个进化独立性的衡量指标与 F(ST)估计值也有相似的相关性，而 F(ST)估计值反过来也显示了物种比较相对于种群比较的相似分布。对基因流动和分离时间的衡量指标进行了检查，以确定它们区分种内差异和种间差异的能力。如果一起使用，这两个指标可以用来开发一种客观的（即可重复的）物种诊断衡量指标。
