Center for Population Biology and Department of Evolution and Ecology, University of California, 1 Shields Ave, Davis, CA 95616, USA.
Mol Ecol. 2010 Feb;19(3):447-58. doi: 10.1111/j.1365-294X.2009.04465.x. Epub 2009 Dec 15.
Phenotypic and genetic divergence can be influenced by a variety of factors, including sexual and natural selection, genetic drift and geographic isolation. Investigating the roles of these factors in natural systems can provide insight into the relative influences of allopatric and ecological modes of biological diversification in nature. The strawberry poison frog, Dendrobates pumilio, presents an excellent opportunity for this kind of research, displaying a diverse array of colour morphs and inhabiting a heterogeneous landscape that includes oceanic islands, fragmented rainforest patches and wide expanses of suitable habitat. In this study, we use 15 highly polymorphic microsatellite loci to estimate population structure and gene flow among populations from across the range of D. pumilio and a causal modelling framework to statistically test 12 hypotheses regarding the geographic and phenotypic variables that explain genetic differentiation within this system. Our results demonstrate that the genetic distance between populations is most strongly associated with differences in dorsal coloration. Previous experimental studies have shown that phenotypic differences can result in sexual and natural selection against non-native phenotypes, and our results now show that these forces lead to genetic isolation between different colour morphs in the wild, presenting a potential case of incipient speciation through selection.
表型和遗传分化可能受到多种因素的影响，包括性选择和自然选择、遗传漂变和地理隔离。在自然系统中研究这些因素的作用可以深入了解异域和生态方式对生物多样性的相对影响。草莓毒蛙（Dendrobates pumilio）为这类研究提供了绝佳的机会，它呈现出多样化的颜色形态，并栖息在包括海洋岛屿、破碎雨林斑块和广泛适宜栖息地的异质景观中。在这项研究中，我们使用了 15 个高度多态的微卫星位点来估计草莓毒蛙种群的遗传结构和基因流，并使用因果建模框架对 12 个关于解释该系统内遗传分化的地理和表型变量的假设进行了统计检验。我们的研究结果表明，种群之间的遗传距离与背部颜色差异密切相关。先前的实验研究表明，表型差异可能导致对非本地表型的性选择和自然选择，我们的研究结果表明，这些力量导致了野外不同颜色形态之间的遗传隔离，从而形成了通过选择形成新物种的潜在案例。
