Carstens B C, Sullivan J, Davalos L M, Larsen P A, Pedersen S C
Box 443051, Department of Biological Sciences, University of Idaho, Moscow 83844-3051, USA.
Mol Ecol. 2004 Sep;13(9):2557-66. doi: 10.1111/j.1365-294X.2004.02250.x.
We explore population genetic structure in phyllostomid bats (Ardops nichollsi, Brachyphylla cavernarum and Artibeus jamaicensis) from the northern Lesser Antilles by investigating the degree to which island populations are genetically differentiated. Our hypothesis, that the island populations are genetically distinct because of a combination of founding events, limited migration and genetic drift exacerbated by catastrophe-induced fluctuations in population size, is derived from a priori hypotheses erected in the literature. The first prediction of this hypothesis, that within each species island populations are monophyletic, was tested using a parametric bootstrap approach. Island monophyly could not be rejected in Ardops nichollsi (P = 0.718), but could be rejected in B. cavernarum (P < 0.001) and Artibeus jamaicensis (P < 0.001). A second prediction, that molecular variance is partitioned among islands, was tested using an amova and was rejected in each species [Ardops nichollsi (P = 0.697); B. cavernarum (P = 0.598); Artibeus jamaicensis (P = 0.763)]. In B. cavernarum and Artibeus jamaicensis, the admixture in mitochondrial haplotypes from islands separated by > 100 km of ocean can be explained either by interisland migration or by incomplete lineage sorting of ancestral polymorphism in the source population. As an a posteriori test of lineage sorting, we used simulations of gene trees within a population tree to suggest that lineage sorting is an unlikely explanation for the observed pattern of nonmonophyly in Artibeus jamaicensis (PW < 0.01; PSE = 0.04), but cannot be rejected in B. cavernarum (PW = 0.81; PSE = 0.79). A conservative interpretation of the molecular data is that island populations of Artibeus jamaicensis, although isolated geographically, are not isolated genetically.
我们通过研究小安的列斯群岛北部叶口蝠（尼氏叶鼻蝠、洞穴短叶蝠和牙买加果蝠）种群的遗传分化程度，来探究其种群遗传结构。我们的假设是，由于奠基事件、有限的迁移以及由灾难引起的种群大小波动加剧的遗传漂变的综合作用，岛屿种群在遗传上是不同的，这一假设源自文献中提出的先验假设。该假设的第一个预测是，在每个物种中岛屿种群是单系的，我们使用参数自展法对其进行了检验。在尼氏叶鼻蝠中不能拒绝岛屿单系性（P = 0.718），但在洞穴短叶蝠（P < 0.001）和牙买加果蝠（P < 0.001）中可以拒绝。第二个预测是分子变异在岛屿间进行分配，我们使用分子方差分析对其进行了检验，并且在每个物种中都被拒绝了[尼氏叶鼻蝠（P = 0.697）；洞穴短叶蝠（P = 0.598）；牙买加果蝠（P = 0.763）]。在洞穴短叶蝠和牙买加果蝠中，来自被超过100公里海洋隔开的岛屿的线粒体单倍型的混合，要么可以通过岛屿间迁移来解释，要么可以通过源种群中祖先多态性的不完全谱系分选来解释。作为谱系分选的事后检验，我们使用种群树内基因树的模拟表明，谱系分选不太可能解释牙买加果蝠中观察到的非单系模式（PW < 0.01；PSE = 0.04），但在洞穴短叶蝠中不能被拒绝（PW = 0.81；PSE = 0.79）。对分子数据的保守解释是，牙买加果蝠的岛屿种群虽然在地理上是隔离的，但在遗传上并非隔离。
