Genomic and acoustic differences separate Lilian’s Meadowlark (Sturnella magna lilianae) from Eastern (S. magna) and Western (S. neglecta) Meadowlarks

Examining differences among recently diverged populations can provide insight into the traits and evolutionary mechanisms that drive or maintain divergence. The genus Sturnella includes two recently diverged species, Sturnella magna (Eastern Meadowlark) and S. neglecta (Western Meadowlark), the former of which has a complex of subspecies distributed across the Americas. Of the S. magna subspecies that occur in the United States, S. m. lilianae is the only one with a disjunct range, occurring in the southwestern U.S. and central Mexico. It also has markedly different song patterns than all other S. magna subspecies. In order to assess population differentiation, we performed whole-genome sequencing of 35 birds, and analyzed song characteristics from 85 birds. Songs from each species and S. m. lilianae were diagnosable using linear discriminant function analysis and support divergence in song between all taxa. Phylogenetic analysis and admixture proportions support three distinct clades w...

研究近期分化种群间的差异，有助于深入理解驱动或维持分化的性状及进化机制。Sturnella属包含两个近期分化的物种——Sturnella magna（东美草地鹨，Eastern Meadowlark）和S. neglecta（西美草地鹨，Western Meadowlark），其中前者拥有一个分布于美洲各地的亚种复合体。在美国分布的S. magna亚种中，S. m. lilianae是唯一具有不连续分布区的亚种，其分布于美国西南部及墨西哥中部。它的鸣唱模式也与其他所有S. magna亚种存在显著差异。为评估种群分化程度，我们对35只鸟类进行了全基因组测序（whole-genome sequencing），并分析了85只鸟类的鸣唱特征。通过线性判别函数分析（linear discriminant function analysis）可区分各物种及S. m. lilianae的鸣唱，这支持了所有类群间的鸣唱分化。系统发育分析（phylogenetic analysis）及混合比例数据支持存在三个不同的分支（clade）w...