Joseph L, Moritz C, Hugall A
Department of Zoology, University of Queensland, Australia.
Proc Biol Sci. 1995 May 22;260(1358):177-82. doi: 10.1098/rspb.1995.0077.
The origin of high diversity in tropical rainforests is attributed to divergence amongst relatively mesic, late Pleistocene refuges. To test this hypothesis we analysed sequence variation within the mitochondrial DNA of populations of six rainforest-dwelling vertebrate species (one lizard and five birds) in the Wet Tropical rainforests of northeastern Australia. Vicariance among historical refuges was indicated by geographically congruent variation across a historical climatic barrier previously predicted by modelling. Sequence divergence across the barrier varied widely, being highest in species with lowest vagility and greatest restriction to rainforest. A high altitude, rainforest-restricted species was exceptional in lacking mtDNA variation. These data support the suggested role of vicariance in promoting evolutionary diversity in rainforests but also indicate variation in the timing of vicariance events, with most speciation or divergence events occurring well before the late Pleistocene. The relation between the amount of molecular divergence and current ecology suggests a sequence of isolation events, perhaps of increasing severity, occurring between the late Tertiary and the late Pleistocene.
热带雨林高生物多样性的起源归因于相对湿润的晚更新世避难所之间的分化。为了验证这一假设，我们分析了澳大利亚东北部湿润热带雨林中六种栖息于雨林的脊椎动物（一种蜥蜴和五种鸟类）种群线粒体DNA内的序列变异。历史避难所之间的隔离通过跨越先前模型预测的历史气候屏障的地理一致变异得以体现。屏障两侧的序列分歧差异很大，在活动性最低且对雨林限制最大的物种中最高。一种高海拔、局限于雨林的物种在缺乏线粒体DNA变异方面是个例外。这些数据支持了隔离在促进雨林进化多样性中所起的作用，但也表明隔离事件的时间存在差异，大多数物种形成或分歧事件发生在晚更新世之前很久。分子分歧量与当前生态之间的关系表明，在晚第三纪到晚更新世期间发生了一系列隔离事件，其严重程度可能不断增加。
