The xeromorphic vegetation is a significant component of the Australian flora and phylogenetic and phylogeographic analysis of xeromorphic plants provides a basis for understanding the origins and evolutionary history of the Australian vegetation. Here we expand on previous reviews of the origins and maintenance of the Australian flora with an emphasis on the xeromorphic component. Phylogenetic evidence supports fossil evidence for evolution of sclerophyll and xeromorphic vegetation from the Eocene with lineages becoming more common in the Oligocene and Miocene, a time of major change in climate and vegetation in Australia. Phylogenetic evidence supports the mesic biome as ancestral to the arid zone biome in Australia in phylogenies of key groups. The diversification and radiation of Australian species shows single origins of xeromorphic group mainly at deeper levels in phylogenies as well as multiple origins of arid occurring species at shallower levels. Divergence across the Nullarbor is also evident and speciation rates in south-western Australia were higher than in the south-east in several plant families. Estimates of timing of diversification generally show either constant rates of diversification or increased diversification from the mid to late Miocene. Phylogeographic studies consistently demonstrate high localised genetic diversity and geographic structure in xeromorphic species occupying both mesic and arid biomes.

中文翻译：

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澳大利亚旱生植被的起源和进化史

干形植被是澳大利亚植物群的重要组成部分，干形植物的系统发育和系统地理学分析为了解澳大利亚植被的起源和进化史提供了基础。在这里，我们扩展了之前对澳大利亚植物群起源和维护的评论，重点是拟态成分。系统发育证据支持硬叶植物和异形植被从始新世进化的化石证据，在渐新世和中新世，澳大利亚气候和植被发生重大变化的时期，谱系变得越来越普遍。系统发育证据支持在关键群体的系统发育中，中生生物群系是澳大利亚干旱区生物群系的祖先。澳大利亚物种的多样化和辐射表明，在系统发育的更深层次上主要是干形群的单一起源，以及在较浅层次上干旱发生物种的多个起源。Nullarbor 的差异也很明显，澳大利亚西南部的几个植物科的物种形成率高于东南部。对多样化时间的估计通常表明，从中新世中期到晚期，多样化的速率恒定或多样化。系统地理学研究一致表明，占据中等和干旱生物群落的异形物种具有高度的局部遗传多样性和地理结构。Nullarbor 的差异也很明显，澳大利亚西南部的几个植物科的物种形成率高于东南部。对多样化时间的估计通常表明，从中新世中期到晚期，多样化的速率恒定或多样化。系统地理学研究一致表明，占据中等和干旱生物群落的异形物种具有高度的局部遗传多样性和地理结构。Nullarbor 的差异也很明显，澳大利亚西南部的几个植物科的物种形成率高于东南部。对多样化时间的估计通常表明，从中新世中期到晚期，多样化的速率恒定或多样化。系统地理学研究一致表明，占据中等和干旱生物群落的异形物种具有高度的局部遗传多样性和地理结构。