Evolution of the Atacama Desert flora: Insights from phylogeographic studies on Oxalis and Viola

拟议的研究将使用系统发育和系统地理方法来解决关于阿塔卡马沙漠植物区系演变的假说。这些假设源于这片沙漠受限的中新世时代，其排水模式的类型和地理方向，以及它靠近安第斯山脉和南锥体植物多样性的主要中心。利用阿塔卡马沿海雾沙漠特有的Viola和Oxis物种的分子遗传数据，我们将调查它们最近的近亲出现在哪里，地理传播的主要方向是什么，以及哪些因素影响区域屏障，例如被称为qubradas的东西流动的排水峡谷对种群结构和物种多样性的影响。初步数据表明，利用叶绿体和核DNA序列、微卫星和AFLP数据的方法是可行的。

The proposed research will use phylogenetic and phylogeographic approaches to address hypotheses about the evolution of the flora of the Atacama Desert. These hypotheses derive from the well-constrained Miocene age of this desert, the type and geographic direction of its drainage patterns, and its proximity to major centres of Andean and Southern Cone plant diversity. Using molecular genetic data for species of Viola and Oxalis endemic to the Atacama coastal fog desert, we will investigate where their closest relatives occur, what the major directions of geographic spread are, and which effects regional barriers, such as the East-West-running water drainage canyons known as quebradas, have on population structure and species diversity. Preliminary data demonstrate the feasibility of an approach that will utilize chloroplast and nuclear DNA sequences, microsatellites, and AFLP data.