Evolutionarily labile dispersal behavior and discontinuous habitats enhance population differentiation in island versus continentally distributed swallows
Evolutionarily labile dispersal behavior and discontinuous habitats enhance population differentiation in island versus continentally distributed swallows
复制标题
进化不稳定的扩散行为和不连续的栖息地增强了岛屿燕子与大陆燕子的种群分化
DOI：
10.1093/evolut/qpad179
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发表时间：
2023
期刊：
影响因子：
3.3
通讯作者：
Hund, Amanda K
中科院分区：
文献类型：
--
作者：
Broyles, Grant G;Myers, Brian M;Friedman, Nicholas R;Gawin, Dency F;Mohd-Taib, Farah S;Sahlan, Penigran G;Seneviratne, Sampath S;de Silva, N Chamalka;Lekamlage, Thilini T;Hund, Amanda K
迷走群体种群分化的原因仍然是进化生物学中的一个悖论：分散的物种应该能够殖民新的地区，这是异域物种形成的先决条件，但分散也促进了基因流动，从而削弱了种群分化。有人认为，强大的扩散能力可以增强斑块状栖息地的分化并抑制连续景观的分化，但这一假设缺乏经验支持。在这里，我们比较了分布在斑驳和连续栖息地的分散燕子分支的种群分化模式。太平洋燕子 (Hirundo tahitica) 在整个东南亚和太平洋岛屿上分布，而它的姊妹种迎宾燕子 (H. neoxena) 在澳大利亚大陆上分布。我们使用全基因组数据来证明岛屿种群中强大的遗传结构和有限的渐渗，但大陆种群中则不然。人口统计模型表明，栖息地连通性的历史性变化对进化枝内的种群结构做出了贡献。燕子似乎表现出进化上不稳定的分散行为，尽管它们保留了强大的飞行能力，但在岛屿殖民后却降低了分散倾向。我们的数据支持这样的假设，即破碎的栖息地增强了迷走群体的种群分化，并表明不稳定的分散行为是这种模式背后的关键机制。
The causes of population divergence in vagile groups remain a paradox in evolutionary biology: dispersive species should be able to colonize new areas, a prerequisite for allopatric speciation, but dispersal also facilitates gene flow, which erodes population differentiation. Strong dispersal ability has been suggested to enhance divergence in patchy habitats and inhibit divergence in continuous landscapes, but empirical support for this hypothesis is lacking. Here we compared patterns of population divergence in a dispersive clade of swallows distributed across both patchy and continuous habitats. The Pacific Swallow (Hirundo tahitica) has an insular distribution throughout Southeast Asia and the Pacific, while its sister species, the Welcome Swallow (H. neoxena), has a continental distribution in Australia. We used whole-genome data to demonstrate strong genetic structure and limited introgression among insular populations, but not among continental populations. Demographic models show that historic changes in habitat connectivity have contributed to population structure within the clade. Swallows appear to exhibit evolutionarily labile dispersal behavior in which they reduce dispersal propensity after island colonization despite retaining strong flight ability. Our data support the hypothesis that fragmented habitats enhance population differentiation in vagile groups, and suggest that labile dispersal behavior is a key mechanism underlying this pattern.