Phylogenomic Data Reveal Widespread Introgression Across the Range of an Alpine and Arctic Specialist
Phylogenomic Data Reveal Widespread Introgression Across the Range of an Alpine and Arctic Specialist
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DOI：
10.1093/sysbio/syaa071
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发表时间：
2021-05-01
影响因子：
6.5
通讯作者：
Taylor, Scott A.
中科院分区：
文献类型：
--
作者：
Funk, Erik R.;Spellman, Garth M.;Taylor, Scott A.
了解基因流如何影响种群分化和物种形成仍然具有挑战性。将一种进化过程与另一种进化过程区分开来可能很困难，因为多个过程可以产生相似的模式，并且多个过程可以同时发生。尽管简单的种群模型可以产生可预测的结果，但这些过程如何在具有斑块分布和复杂自然历史的类群中保持平衡还不太确定。这些类型的种群可能通过迁移（基因流）而高度相连，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。尽管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许多这些过程所需的分辨率。我们提供了分布在高山和北极苔原的鸟类物种组的全基因组序列数据，以研究不同种群遗传过程在其进化历史中所发挥的作用。红雀栖息于高海拔山顶天空岛屿以及高纬度岛屿和大陆苔原。它们表现出广泛的羽毛变异和低水平的遗传变异。此外，复合体中物种的数量存在争议，这使得它们非常适合研究多样化过程中涉及的力量，以及调查物种边界的重要物种组。总基因组变异表明北美该类群的大陆类群的等位基因频率变化存在广泛连续的模式。然而，系统基因组分析恢复了多个不同的、得到充分支持的群体，这些群体与之前描述的形态变异和当前的物种水平分类学相一致。使用 D 统计和近似贝叶斯计算进行的基因渗入测试揭示了多个北美分类单元之间显着的基因渗入水平。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深入了解，并强调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方面仍然存在的挑战。
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. Although 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. Although 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.