Biodiversity and Geosciences Program, Queensland Museum, South Brisbane, QLD 4101, Australia; Collections and Research Centre, Western Australian Museum, Welshpool, WA 6106, Australia.
Biodiversity and Geosciences Program, Queensland Museum, South Brisbane, QLD 4101, Australia; Division of Arachnology, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina.
Mol Phylogenet Evol. 2021 Jul;160:107127. doi: 10.1016/j.ympev.2021.107127. Epub 2021 Mar 2.
The assembly of the Australian arid zone biota has long fascinated biogeographers. Covering over two-thirds of the continent, Australia's vast arid zone biome is home to a distinctive fauna and flora, including numerous lineages which have diversified since the Eocene. Tracing the origins and speciation history of these arid zone taxa has been an ongoing endeavour since the advent of molecular phylogenetics, and an increasing number of studies on invertebrate animals are beginning to complement a rich history of research on vertebrate and plant taxa. In this study, we apply continent-wide genetic sampling and one of the largest phylogenetic data matrices yet assembled for a genus of Australian spiders, to reconstruct the phylogeny and biogeographic history of the open-holed trapdoor spider genus Aname L. Koch, 1873. This highly diverse lineage of Australian mygalomorph spiders has a distribution covering the majority of Australia west of the Great Dividing Range, but apparently excluding the high rainfall zones of eastern Australia and Tasmania. Original and legacy sequences were obtained for three mtDNA and four nuDNA markers from 174 taxa in seven genera, including 150 Aname specimen terminals belonging to 102 species-level operational taxonomic units, sampled from 32 bioregions across Australia. Reconstruction of the phylogeny and biogeographic history of Aname revealed three radiations (Tropical, Temperate-Eastern and Continental), which could be further broken into eight major inclusive clades. Ancestral area reconstruction revealed the Pilbara, Monsoon Tropics and Mid-West to be important ancestral areas for the genus Aname and its closest relatives, with the origin of Aname itself inferred in the Pilbara bioregion. From these origins in the arid north-west of Australia, our study found evidence for a series of subsequent biome transitions in separate lineages, with at least eight tertiary incursions back into the arid zone from more mesic tropical, temperate or eastern biomes, and only two major clades which experienced widespread (primary) in situ diversification within the arid zone. Based on our phylogenetic results, and results from independent legacy divergence dating studies, we further reveal the importance of climate-driven biotic change in the Miocene and Pliocene in shaping the distribution and composition of the Australian arid zone biota, and the value of continent-wide studies in revealing potentially complex patterns of arid zone diversification in dispersal-limited invertebrate taxa.
澳大利亚干旱区生物群的组合一直令生物地理学家着迷。澳大利亚广阔的干旱区生物群落覆盖了大陆的三分之二以上，是独特的动植物群的家园，包括自始新世以来多样化的众多谱系。自从分子系统发生学出现以来，追踪这些干旱区分类群的起源和物种形成历史一直是一项持续的努力，越来越多的无脊椎动物研究开始补充对脊椎动物和植物分类群的丰富研究历史。在这项研究中，我们应用了全大陆范围的遗传采样，以及迄今为澳大利亚蜘蛛属之一收集的最大的系统发育数据集之一，来重建开放式陷阱门蜘蛛属 Aname L. Koch 的系统发育和生物地理历史，1873 年。这个高度多样化的澳大利亚肌胃蛛谱系的分布范围覆盖了大分水岭以西的澳大利亚大部分地区，但显然不包括澳大利亚东部和塔斯马尼亚的高降雨区。从七个属的 174 个分类群中获得了三个 mtDNA 和四个 nuDNA 标记的原始和遗留序列，包括属于 102 个种级操作分类单元的 150 个 Aname 标本末端，这些标本是从澳大利亚 32 个生物区系中采集的。Aname 的系统发育和生物地理历史重建揭示了三次辐射（热带、温带东部和大陆），可进一步细分为八个主要包容分支。祖先区重建显示，皮尔巴拉、季风热带地区和中西部是该属及其最亲近的亲缘关系的重要祖先区，而 Aname 的起源则被推断为在皮尔巴拉生物区系中。从澳大利亚干旱的西北部的这些起源地，我们的研究发现了一系列随后在单独谱系中发生的生物群落过渡的证据，至少有八个第三纪入侵从更潮湿的热带、温带或东部生物群落返回干旱区，只有两个主要分支在干旱区经历了广泛的（主要）原地多样化。根据我们的系统发育结果和独立的遗留分歧日期研究结果，我们进一步揭示了中新世和上新世气候驱动的生物变化在塑造澳大利亚干旱区生物群的分布和组成方面的重要性，以及全大陆研究在揭示扩散受限的无脊椎动物分类群中可能复杂的干旱区多样化模式方面的价值。
