Fahey Patrick S, Fowler Rachael M, McLay Todd G B, Udovicic Frank, Cantrill David J, Bayly Michael J
School of BioSciences The University of Melbourne Parkville Vic. Australia.
Royal Botanic Gardens Victoria South Yarra Vic. Australia.
Ecol Evol. 2020 Dec 15;11(1):664-678. doi: 10.1002/ece3.7099. eCollection 2021 Jan.
To infer relationships between populations of the semi-arid, mallee eucalypt, , to build hypotheses regarding evolution of major disjunctions in the species' distribution and to expand understanding of the biogeographical history of southeastern Australia.
Southeastern Australia.
(Myrtaceae, Angiospermae).
We developed a large dataset of anonymous genomic loci for 97 samples from 11 populations of using double digest restriction site-associated DNA sequencing (ddRAD-seq), to determine genetic relationships between the populations. These relationships, along with species distribution models, were used to construct hypotheses regarding environmental processes that have driven fragmentation of the species' distribution.
Greatest genetic divergence was between populations on either side of the Lower Murray Basin. Populations west of the Basin showed greater genetic divergence between one another than the eastern populations. The most genetically distinct population in the east (Long Forest) was separated from others by the Great Dividing Range. A close relationship was found between the outlying northernmost population (near West Wyalong) and those in the Victorian Goldfields despite a large disjunction between them.
Patterns of genetic variation are consistent with a history of vicariant differentiation of disjunct populations. We infer that an early disjunction to develop in the species distribution was that across the Lower Murray Basin, an important biogeographical barrier separating many dry sclerophyll plant taxa in southeastern Australia. Additionally, our results suggest that the western populations fragmented earlier than the eastern ones. Fragmentation, both west and east of the Murray Basin, is likely tied to climatic changes associated with glacial-interglacial cycles although it remains possible that major geological events including uplift of the Mount Lofty Ranges and basalt flows in the Newer Volcanics Province also played a role.
推断半干旱地区的马利桉种群之间的关系，构建有关该物种分布中主要间断进化的假设，并拓展对澳大利亚东南部生物地理历史的理解。
澳大利亚东南部。
（桃金娘科，被子植物）。
我们使用双酶切限制性位点关联DNA测序（ddRAD-seq）技术，为来自11个种群的97个样本开发了一个包含匿名基因组位点的大型数据集，以确定种群之间的遗传关系。这些关系以及物种分布模型被用于构建有关驱动该物种分布碎片化的环境过程的假设。
最大的遗传差异存在于下墨累盆地两侧的种群之间。盆地以西的种群彼此之间的遗传差异大于东部种群。东部遗传上最独特的种群（长林）被大分水岭与其他种群隔开。尽管最北端的外围种群（靠近西怀亚隆）与维多利亚金矿地区的种群之间存在很大的间断，但发现它们之间关系密切。
遗传变异模式与间断种群的替代分化历史一致。我们推断，该物种分布中最早出现的间断是跨越下墨累盆地，这是澳大利亚东南部一个重要的生物地理屏障，将许多旱生硬叶植物类群分隔开来。此外，我们的结果表明，西部种群比东部种群更早出现碎片化。墨累盆地东西部的碎片化可能与冰期-间冰期循环相关的气候变化有关，尽管包括洛夫蒂山脉隆升和新火山省玄武岩流在内的重大地质事件也可能起到了作用。
