Population structure, dispersal and colonization history of the garden bumblebee Bombus hortorum in the Western Isles of Scotland
Population structure, dispersal and colonization history of the garden bumblebee Bombus hortorum in the Western Isles of Scotland
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DOI：
10.1007/s10592-011-0190-4
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发表时间：
2011-08-01
影响因子：
2.2
通讯作者：
Darvill, B.
中科院分区：
文献类型：
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作者：
Goulson, D.;Kaden, J. C.;Darvill, B.
分析遗传数据的新方法为量化扩散模式和重建种群历史提供了强有力的工具。在这里，我们研究的人口结构熊蜂hortorum在一个模型岛屿系统，苏格兰西部群岛，使用微卫星标记。继其他物种的下降，B。hortorum是欧洲大部分地区仅存的长舌熊蜂物种，因此具有特殊的生态重要性。我们的数据表明，B.苏格兰西部的hortorum作为不同的遗传集群存在，占据了附近的岛屿群。人口结构高于其他熊蜂物种，以前已经研究了在同一个岛屿组（F-ST = 0.16）。人口显示出显着的隔离距离。这种关系大大改善了电路理论，使扩散率不同的景观功能，正如我们所预测的，海洋似乎提供了更高的阻力比陆地扩散。对水深测量数据的分析进一步提高了模型的拟合度;被浅海分隔的种群在遗传上比被深海分隔的种群更为相似。我们认为，这可能反映了最后一个冰河时代之后的事件，当时这些岛屿首次被这种蜜蜂物种殖民（8，500 - 5，000 ybp），当时海平面较低，被浅通道隔开的岛屿将被连接起来。在没有显著的基因流动的情况下，这些基因簇似乎在接下来的5,000年里发生了分歧，可以说现在可能代表了当地适应的种族，有些发生在单个岛屿上。
New methods of analysing genetic data provide powerful tools for quantifying dispersal patterns and reconstructing population histories. Here we examine the population structure of the bumblebee Bombus hortorum in a model island system, the Western Isles of Scotland, using microsatellite markers. Following declines in other species, B. hortorum is the only remaining long-tongued bumblebee species found in much of Europe, and thus it is of particular ecological importance. Our data suggest that populations of B. hortorum in western Scotland exist as distinct genetic clusters occupying groups of nearby islands. Population structuring was higher than for other bumblebee species which have previously been studied in this same island group (F-st = 0.16). Populations showed significant isolation by distance. This relationship was greatly improved by using circuit theory to allow dispersal rates to differ over different landscape features; as we would predict, sea appears to provide far higher resistance to dispersal than land. Incorporating bathymetry data improved the fit of the model further; populations separated by shallow seas are more genetically similar than those separated by deeper seas. We argue that this probably reflects events following the last ice age when the islands were first colonized by this bee species (8,500-5,000 ybp), when the sea levels were lower and islands separated by shallow channels would have been joined. In the absence of significant gene flow these genetic clusters appear to have since diverged over the following 5,000 years and arguably may now represent locally adapted races, some occurring on single islands.