Understanding how gene flow affects population divergence and speciation remains challenging. Differentiating one evolutionary process from another can be difficult because multiple processes can produce similar patterns, and more than one process can occur simultaneously. While simple population models produce predictable results, how these processes balance in taxa with patchy distributions and complicated natural histories is less certain. These types of populations might be highly connected through migration (gene flow), but can experience stronger effects of genetic drift and inbreeding, or localized selection. While different signals can be difficult to separate, the application of high throughput sequence data can provide the resolution necessary to distinguish many of these processes. We present whole genome sequence data for an avian species group with an alpine and arctic tundra distribution to examine the role that different population genetic processes have played in their evolutionary history. Rosy-finches inhabit high elevation mountaintop sky islands and high-latitude island and continental tundra. They exhibit extensive plumage variation coupled with low levels of genetic variation. Additionally, the number of species within the complex is debated, making them excellent for studying the forces involved in the process of diversification, as well as an important species group in which to investigate species boundaries. Total genomic variation suggests a broadly continuous pattern of allele frequency changes across the mainland taxa of this group in North America. However, phylogenomic analyses recover multiple distinct, well supported, groups that coincide with previously described morphological variation and current species-level taxonomy. Tests of introgression using D-statistics and approximate Bayesian computation reveal significant levels of introgression between multiple North American taxa. These results provide insight into the balance between divergent and homogenizing population genetic processes and highlight remaining challenges in interpreting conflict between different types of analytical approaches with whole genome sequence data.

中文翻译：

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系统基因组数据揭示了高山和北极专家范围内广泛的基因渗入

了解基因流动如何影响种群分化和物种形成仍然具有挑战性。将一个进化过程与另一个区分开来可能很困难，因为多个过程可以产生相似的模式，并且可以同时发生多个过程。虽然简单的种群模型会产生可预测的结果，但这些过程如何在分类群中与不完整的分布和复杂的自然历史保持平衡却不太确定。这些类型的种群可能通过迁移（基因流动）高度连接，但可能会受到遗传漂变和近亲繁殖或局部选择的更强影响。虽然不同的信号可能难以分离，但高通量序列数据的应用可以提供区分这些过程所需的分辨率。我们提供了具有高山和北极苔原分布的鸟类物种群的全基因组序列数据，以检查不同种群遗传过程在其进化历史中所起的作用。红雀栖息于高海拔山顶天空岛屿和高纬度岛屿和大陆苔原。它们表现出广泛的羽毛变异以及低水平的遗传变异。此外，该综合体中的物种数量存在争议，使其非常适合研究多样化过程中涉及的力量，以及研究物种边界的重要物种群。总基因组变异表明北美该组大陆分类群的等位基因频率变化具有广泛连续的模式。然而，系统基因组分析恢复了多个不同的，得到很好的支持，与先前描述的形态变异和当前物种级分类相一致的组。使用 D 统计量和近似贝叶斯计算的基因渗入测试揭示了多个北美分类群之间的显着水平的基因渗入。这些结果提供了对不同和同质化群体遗传过程之间平衡的洞察，并突出了在解释不同类型的分析方法与全基因组序列数据之间的冲突时仍存在​​的挑战。