Invasion genetics of New World medflies: Testing alternative colonization scenarios
Invasion genetics of New World medflies: Testing alternative colonization scenarios
复制标题
DOI：
10.1023/a:1014559617282
复制
发表时间：
2001-01-01
影响因子：
2.9
通讯作者：
Roderick, George K.
中科院分区：
文献类型：
--
作者：
Bohonak, Andrew J.;Davies, Neil;Roderick, George K.
地中海实蝇是一种侵袭性农业害虫，寄主范围广，几乎遍布全球。阻止麻蝇扩散到美国的努力取决于对其他地方新建立的种群的种群动态的了解。为了探索人口统计和历史参数对分布在墨西哥到秘鲁的六个种群的潜在影响，我们使用蒙特卡罗模拟建立了种群遗传零模型。将遗传分化的零期望(FST)与4个高度多态的核基因座的实际序列变异进行了比较。模拟的四种殖民情景导致了独特的基因签名，可以用来解释经验数据。除非目前拉丁美洲的基因流动被认为是非常高的，否则我们可以拒绝由多个导入组成的殖民，每个导入都具有低遗传多样性。此外，如果模拟种群很小(Ne=5X102个/种群)，来自单一来源的小入侵始终产生与目前在拉丁美洲观察到的FST值相当的FST值。相反，只有来自不同来源的大规模入侵与大量种群的观察数据相一致(Negtoreq5X103)。这项研究表明，即使在偏离平衡的极端情况下，可供选择的种群遗传假说也可以得到经验检验，并且种群遗传学理论可以用来探索生物入侵的基础过程。
The Mediterranean fruit fly (Ceratitis capitata) is an invasive agricultural pest with a wide host range and a nearly global distribution. Efforts to forgo the medfly's spread into the United States are dependent on an understanding of population dynamics in newly established populations elsewhere. To explore the potential influence of demographic and historical parameters in six medfly populations distributed from Mexico to Peru, we created population genetic null models using Monte Carlo simulations. Null expectations for genetic differentiation (FST) were compared with actual sequence variation from four highly polymorphic nuclear loci. Four colonization scenarios that were modeled led to unique genetic signatures that could be used to interpret empirical data. Unless current gene flow across Latin America was assumed to be very high, we could reject colonizations consisting of multiple introductions, each of low genetic diversity. Further, if simulated populations were small (Ne=5X102 individuals per population), small invasions from a single source consistently produced FST values comparable to those currently observed in Latin America. In contrast, only large invasions from diverse sources were compatible with the observed data for large populations (Negtoreq5X103). This study demonstrates that alternative population genetic hypotheses can be tested empirically even when departures from equilibrium are extreme, and that population genetic theory can be used to explore the processes that underlie biological invasions.