Norambuena Heraldo V, Van Els Paul, Muñoz-Ramírez Carlos P, Victoriano Pedro F
Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile.
Centro de Estudios Agrarios y Ambientales, Valdivia, Chile.
PeerJ. 2018 Nov 21;6:e5886. doi: 10.7717/peerj.5886. eCollection 2018.
Grasslands in southern South America are extensive ecosystems which harbor a unique biodiversity; however, studies on the evolution of their taxa are scarce. Here we studied the phylogeography and population history of the Correndera Pipit (), a grassland specialist bird with a large breeding distribution in southern South America, with the goals of investigating its phylogeographic history and relate it to the historical development of South American grasslands. The mitochondrial NADH dehydrogenase subunit II gene (ND2) was sequenced in 66 individuals from 19 localities and the intron 9 of the sex-linked gene for aconitase (ACOI9) was sequenced from a subset of those individuals, including all five subspecies of , as well as the closely related . Phylogenetic analysis revealed two distinct lineages within the complex: the first (A) corresponding to Andean subspecies and and the second (B) including birds traditionally assigned to , , and some individuals of . is nested within this second lineage. These results were also supported by evidence of niche divergence for variables associated with precipitation. The oldest split between clade A and B was estimated at 0.37 Mya, during the middle Pleistocene. Species distribution models for the present and the Last Glacial Maximum (LGM) suggest that grassland areas in southern South America remained relatively stable, in contrast to the general view of a reduction in grassland cover in South America since the LGM. Recent divergences and low phylogeographic structure (for lowland vs. highland geographic groups, intra-population genetic variance was greater than inter-groups; e.g., for ACOI9: 95.47% and ND2: 51.51% respectively), suggest widespread gene flow between lowland populations.
南美洲南部的草原是广阔的生态系统，拥有独特的生物多样性；然而，关于其分类群进化的研究却很稀少。在这里，我们研究了科伦德雷拉鹨（）的系统地理学和种群历史，这是一种在南美洲南部具有广泛繁殖分布的草原特化鸟类，目的是调查其系统地理历史，并将其与南美洲草原的历史发展联系起来。对来自19个地点的66个个体的线粒体NADH脱氢酶亚基II基因（ND2）进行了测序，并从这些个体的一个子集中对与乌头酸酶相关的性连锁基因的内含子9（ACOI9）进行了测序，其中包括的所有五个亚种以及与之密切相关的。系统发育分析揭示了该复合体中的两个不同谱系：第一个（A）对应于安第斯亚种和，第二个（B）包括传统上归为、、和一些个体的鸟类。嵌套在第二个谱系中。与降水相关变量的生态位分化证据也支持了这些结果。A和B分支之间最古老的分歧估计发生在中更新世，约0.37百万年前。当前和末次盛冰期（LGM）的物种分布模型表明，南美洲南部的草原地区保持相对稳定，这与自LGM以来南美洲草原覆盖面积减少的普遍观点形成对比。近期的分化和低系统地理结构（对于低地与高地地理群体，种群内遗传方差大于群体间；例如，对于ACOI9分别为95.47%，对于ND2为51.51%）表明低地种群之间存在广泛的基因流动。
