Department of Animal Behaviour, Bielefeld University Morgenbreede 45, 33615, Bielefeld, Germany.
Biodiversity and Ecological Processes Group, Cardiff School of Biosciences, Cardiff University Cardiff, CF10 3AX, U.K.
Ecol Evol. 2015 Mar;5(5):997-1010. doi: 10.1002/ece3.1393. Epub 2015 Jan 23.
Understanding the relative contributions of intrinsic and extrinsic factors to population structure and genetic diversity is a central goal of conservation and evolutionary genetics. One way to achieve this is through comparative population genetic analysis of sympatric sister taxa, which allows evaluation of intrinsic factors such as population demography and life history while controlling for phylogenetic relatedness and geography. We used ten conserved microsatellites to explore the population structure and genetic diversity of three sympatric and closely related plover species in southwestern Madagascar: Kittlitz's plover (Charadrius pecuarius), white-fronted plover (C. marginatus), and Madagascar plover (C. thoracicus). Bayesian clustering revealed strong population structure in the rare and endemic Madagascar plover, intermediate population structure in the white-fronted plover, and no detectable population structure in the geographically widespread Kittlitz's plover. In contrast, allelic richness and heterozygosity were highest for the Kittlitz's plover, intermediate for the white-fronted plover and lowest for the Madagascar plover. No evidence was found in support of the "watershed mechanism" proposed to facilitate vicariant divergence of Madagascan lemurs and reptiles, which we attribute to the vagility of birds. However, we found a significant pattern of genetic isolation by distance among populations of the Madagascar plover, but not for the other two species. These findings suggest that interspecific variation in rarity, endemism, and dispersal propensity may influence genetic structure and diversity, even in highly vagile species.
了解内在和外在因素对种群结构和遗传多样性的相对贡献是保护和进化遗传学的核心目标。一种实现这一目标的方法是通过对同域姐妹分类群进行比较种群遗传分析，这可以评估内在因素，如种群人口统计学和生活史，同时控制系统发育关系和地理因素。我们使用十个保守的微卫星来探索马达加斯加西南部三种同域且密切相关的滨鸟的种群结构和遗传多样性：红胸滨鹬（Charadrius pecuarius）、白额滨鹬（C. marginatus）和马达加斯加滨鹬（C. thoracicus）。贝叶斯聚类揭示了稀有和特有物种马达加斯加滨鹬的强烈种群结构，白额滨鹬的中等种群结构，以及广泛分布的红胸滨鹬的无法检测到的种群结构。相比之下，红胸滨鹬的等位基因丰富度和杂合度最高，白额滨鹬居中，而马达加斯加滨鹬最低。没有证据支持“分水岭机制”，该机制被认为有助于马达加斯加狐猴和爬行动物的趋异分化，但我们认为这是鸟类的迁移能力所致。然而，我们发现马达加斯加滨鹬的种群之间存在显著的遗传隔离与距离相关模式，但其他两个物种没有。这些发现表明，稀有程度、特有性和扩散倾向的种间变异可能会影响遗传结构和多样性，即使在高度迁移的物种中也是如此。
