Dolman Gaynor, Moritz Craig
School of Integrative Biology, University of Queensland, St Lucia, Australia.
Evolution. 2006 Mar;60(3):573-82.
To explore the evolutionary consequences of climate-induced fluctuations in distribution of rainforest habitat we contrasted demographic histories of divergence among three lineages of Australian rainforest endemic skinks. The red-throated rainbow skink, Carlia rubrigularis, consists of morphologically indistinguishable northern and southern mitochondrial DNA (mtDNA) lineages that are partially reproductively isolated at their parapatric boundary. The third lineage (C. rhomboidalis) inhabits rainforests just to the south of C. rubrigularis, has blue, rather than red-throated males, and for mtDNA is more closely related to southern C. rubrigularis than is northern C. rubrigularis. Multigene coalescent analyses supported more recent divergence between morphologically distinct lineages than between morphologically conservative lineages. There was effectively no migration and therefore stronger isolation between southern C. rubrigularis and C. rhomboidalis, and low unidirectional migration between morphologically conservative lineages of C. rubrigularis. We found little or no evidence for strong differences in effective population size, and hence different contributions of genetic drift in the demographic history of the three lineages. Overall the results suggest contrasting responses to long-term fluctuations in rainforest habitats, leading to varying opportunities for speciation.
为了探究气候引起的雨林栖息地分布波动的进化后果，我们对比了澳大利亚雨林特有石龙子三个谱系之间分化的种群历史。红喉虹蜥（Carlia rubrigularis）由形态上难以区分的北部和南部线粒体DNA（mtDNA）谱系组成，它们在邻域边界处部分生殖隔离。第三个谱系（C. rhomboidalis）栖息在C. rubrigularis以南的雨林中，雄性为蓝色而非红色喉部，并且就mtDNA而言，它与南部的C. rubrigularis比与北部的C. rubrigularis关系更密切。多基因合并分析支持形态不同的谱系之间的分化比形态保守的谱系之间的分化更近。实际上，南部的C. rubrigularis和C. rhomboidalis之间没有迁移，因此隔离更强，而C. rubrigularis形态保守的谱系之间存在低单向迁移。我们几乎没有发现有效种群大小存在强烈差异的证据，因此在这三个谱系的种群历史中，遗传漂变的贡献也没有差异。总体而言，结果表明对雨林栖息地长期波动的反应不同，导致物种形成的机会各异。
