PhD Thesis: Tracing Molecular Patterns of Adaptation in Arctic Brassicaceae

Extreme environments can function as natural laboratories for studying how different organisms adapt to similar selection pressures at the genetic level. This thesis explores how three Arctic plant species independently adapted to some of the coldest biomes on Earth, and how they evolved similar suites of adaptations to extremes in light and temperature. It addresses fundamental questions in plant evolutionary biology, such as the extent to which adaptation follows the same genetic trajectories in different species, and the genetic basis for plant adaptation to extreme environments. The thesis has two main objectives that are addressed through three papers (Papers I-III): 1) estimate the degree of adaptive molecular convergence in the three Arctic Brassicaceae Cardamine bellidifolia, Cochlearia groenlandica, and Draba nivalis, and 2) identify putative molecular adaptations to the Arctic environment in the same three species.

Approach. The first two papers examine the degree of evolut...

极端环境可作为天然实验室，用于探究不同生物体在遗传层面如何适应相似的选择压力。本论文探究了三种北极植物物种如何独立适应地球上部分最寒冷的生物群落，以及它们如何演化出应对光照与温度极端条件的相似适应性组合。本研究旨在解答植物进化生物学中的核心科学问题，例如不同物种的适应性在多大程度上遵循相同的遗传路径，以及植物适应极端环境的遗传基础。本论文通过三篇研究论文（论文I至III）达成两项核心研究目标：其一，量化评估三种北极十字花科（Brassicaceae）植物——露珠碎米荠（Cardamine bellidifolia）、格陵兰岩荠（Cochlearia groenlandica）以及雪山葶苈（Draba nivalis）——的适应性分子趋同程度；其二，在上述三个物种中鉴定出适应北极环境的潜在分子适应性特征。
研究方法。前两篇论文探究了演化的……