Museo de Zoología "Alfonso L. Herrera", Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico.
Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, Mexico; Consejo Nacional de Ciencia y Tecnología, Mexico.
Mol Phylogenet Evol. 2022 May;170:107445. doi: 10.1016/j.ympev.2022.107445. Epub 2022 Feb 18.
The Velazquez Woodpecker Melanerpes santacruzi is a highly polytypic species distributed from east-central Mexico to northern Nicaragua. The ample variation in body size, barring of the plumage, and the coloration of nasal tufts, neck, and belly have fueled debates about the taxonomy and evolutionary history of the species; however, the processes generating these patterns of variation and the underlying population dynamics throughout the species' distribution remain poorly understood. Here, we employed reduced representation genome sequencing (NextRAD) and Ecological Niche Modeling methods to test the distinctiveness of the Velazquez Woodpecker based on this new set of genomic data and analyze the correspondence of the genetic structure and ecological differentiation with phenotypic variation and geographic distribution. From phylogenetic and demographic analyses including the Golden-Fronted (M. aurifrons) and Red-bellied Woodpecker (M. carolinus), we obtained results congruent with previous molecular phylogenies. The clades of M. santacruzi and M. carolinus-M. aurifrons are reciprocally monophyletic, although the sister group relationship of M. aurifrons is ambiguous. Using genetic and ecological analyses, we found that the species is structured into three genetically and ecologically differentiated groups comprising the subspecies (1) M. s. santacruzi, (2) M. s. dubius and (3) M. s. grateloupensis-polygrammus-veraecrucis. These groups diverged recently, with two splits between 250,000 and 150,000 years ago, and show a significant genetic admixture among them, especially in their current contact zones. Ecological and demographic models suggest the existence of intermittent areas of sympatry and connectivity among populations of M. santacruzi since the Last Interglacial period. We also found evidence of bi-directional gene flow between the species M. aurifrons and the nearby populations of M. santacruzi (M. s. grateloupensis), along the Sierra Madre Oriental in northeastern Mexico. Gene flow seems to be uneven, with prevalence of movement in the direction from M. aurifrons to M. s. grateloupensis.
黑额阔嘴鸟是一个高度多态种，分布范围从墨西哥中东部到尼加拉瓜北部。身体大小、羽毛斑纹、鼻羽、颈部和腹部颜色的巨大差异，引发了关于该物种分类学和进化历史的争论；然而，产生这些变异模式的过程以及整个物种分布范围内的潜在种群动态仍然知之甚少。在这里，我们采用简化基因组测序（NextRAD）和生态位模型方法，根据这组新的基因组数据来测试 Velazquez 啄木鸟的独特性，并分析遗传结构和生态分化与表型变异和地理分布的对应关系。从包括金额（M. aurifrons）和红腹（M. carolinus）在内的系统发育和人口动态分析中，我们得到了与以前分子系统发育一致的结果。M. santacruzi 和 M. carolinus-M. aurifrons 的进化枝是相互单系的，尽管 M. aurifrons 的姐妹群关系尚不清楚。通过遗传和生态分析，我们发现该物种分为三个在遗传和生态上分化的群体，包括亚种（1）M. s. santacruzi、（2）M. s. dubius 和（3）M. s. grateloupensis-polygrammus-veraecrucis。这些群体最近才分化出来，在 25 万至 15 万年前发生了两次分裂，并且在它们之间存在显著的遗传混合，尤其是在它们目前的接触区。生态和人口动态模型表明，自上一个间冰期以来，M. santacruzi 种群之间存在间断的共生和连通区。我们还发现，在墨西哥东北部的 Sierra Madre Oriental 沿线，M. aurifrons 与附近的 M. santacruzi（M. s. grateloupensis）种群之间存在双向基因流动的证据。基因流动似乎不平衡，从 M. aurifrons 到 M. s. grateloupensis 的方向更为普遍。
