Examining differences among recently diverged populations can provide insight into the traits and evolutionary mechanisms that drive or maintain divergence. The genus Sturnella includes 2 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 United States 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 3 distinct clades within North American meadowlarks, and tests of introgression failed to detect a significant signal. Overall, our results indicate that S. m. lilianae exhibits high levels of genetic and vocal differentiation from both S. magna and S. neglecta, with no evidence of introgression between any group, and forms a distinct evolutionary lineage. We thus recommend the elevation of S. m. lilianae to species status.

中文翻译：

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基因组和声学差异将莉莲的草地鹨 (Sturnella magna lilianae) 与东方 (S. magna) 和西方 (S. ignorea) 草地鹨区分开来

检查最近分化的种群之间的差异可以深入了解驱动或维持分化的特征和进化机制。Sturnella 属包括 2 个最近分化的物种，Sturnella magna（东部草地鹨）和 S. ignorea（西部草地鹨），前者具有分布在美洲的多个亚种。在美国出现的 S. magna 亚种中，S. m. lilianae 是唯一一种分布范围不同的植物，分布在美国西南部和墨西哥中部。它的歌唱模式也明显不同于所有其他 S. magna 亚种。为了评估种群分化，我们对 35 只鸟进行了全基因组测序，并分析了 85 只鸟的鸣叫特征。来自每个物种的歌曲和 S. m. 使用线性判别函数分析可以诊断百合亚科，并支持所有分类群之间歌曲的分歧。系统发育分析和混合比例支持北美草地鹨内 3 个不同的进化枝，并且基因渗入测试未能检测到显着信​​号。总的来说，我们的结果表明 S. m. lilianae 与 S. magna 和 S. ignorea 表现出高水平的遗传和声音分化，没有任何群体之间渗入的证据，并形成了独特的进化谱系。因此，我们推荐 S. m. 的高度。百合科的物种地位。我们的结果表明，S. m。lilianae 与 S. magna 和 S. ignorea 表现出高水平的遗传和声音分化，没有任何群体之间渗入的证据，并形成了独特的进化谱系。因此，我们推荐 S. m. 的高度。百合科的物种地位。我们的结果表明，S. m。lilianae 与 S. magna 和 S. ignorea 表现出高水平的遗传和声音分化，没有任何群体之间渗入的证据，并形成了独特的进化谱系。因此，我们推荐 S. m. 的高度。百合科的物种地位。