Systematics, biogeography and evolution of northern floras

系统分类学的一个中心目标是确定在空间和时间上形成多样性的过程。北方植物群提供了这样做的有趣机会，因为它们经历了过去气候变化最激烈的一些时期。我的长期研究目标是发现，分类和保护北方植物的令人敬畏的生物多样性，并确定负责产生和维持这种多样性的过程。为了实现这一目标，我将集中在三个短期目标，将阐明过去的气候变化对北方植物区系在三个进化尺度的演变的影响：宏观进化（目标1），微观进化（目标2），和生态（目标3）。 目的1是量化历史气候变化对莎草科（超过1000种化石）多样性和进化的影响。我们将首先编制一个全面的数据库，所有化石的文献报道，并重新评估其分类的亲缘关系，通过几何形态测量分析（BSC 1）。由此产生的化石数据集将在被子植物中具有前所未有的规模和质量，从而能够对过去1亿年中跨越莎草科进化历史的植物多样化动态，植物地理学，生态位进化和果实进化进行高分辨率分析。目的二是开发第一批莎草科基因组资源，并利用它们来确定气候如何影响杂交和渐渗的频率。两个苔草基因组将组装到染色体规模（博士1），在低成本的实验杂交，这将允许估计的时间和强度的古老的渗入事件，渗入基因组块的长度的基础上。我们还将扩大我们以前的调查，在莎草科宿主-寄生虫的相互作用，利用炭疽总科真菌，优先寄生的杂交，作为代理推断杂交的频率在深时间（MSC 2）。目标3将是加速对淡水潮汐植物群的分类研究，这是一个丰富但受到威胁的北美特有中心。通过平行的分类学和人口基因组研究莎草科（BSC 2，MSC 3）和菊科（博士2）谱系特有的这植物群，我们将发现共享的遗传多样性模式，可用于优先考虑最独特的人口和地区的保护。然后，我们将组装一个完整的分布数据库的所有类群发生在淡水潮汐植物群（c。100种; BSc 3）测试区域，气候条件和河口之间的距离如何影响地方性，丰富性，系统发育多样性和种群遗传多样性（PhD 2）。这种综合方法将使我们能够发现大规模的历史和生态过程，这些过程在生物复杂性的各个层面上形成多样性，从基因到物种和整个社区。

A central aim of systematics is to identify the processes that shape diversity across space and time. Northern floras offer interesting opportunities to do so, as they have been through some of the most intense periods of past climate change. My long term research goal is to discover, classify and protect the awe-inspiring biodiversity of northern plants, and to identify the processes responsible for generating and maintaining this diversity. Towards this goal, I will focus on three short-term objectives that will shed light on the impact of past climate change on evolution of northern floras at three evolutionary scales: macro-evolutionary (Objective 1), micro-evolutionary (Objective 2), and ecological (Objective 3). Objective 1 is to quantify the influence of historical climate change on the diversity and evolution of one of the most abundant plant families in the fossil record, Cyperaceae (>1000 fossils). We will first compile a comprehensive database of all fossils reported in the literature, and re-assess their taxonomic affinities through geometric morphometric analysis (BSc 1). The resulting fossil dataset will be of unprecedented size and quality in angiosperms, enabling high-resolution analysis of plant diversification dynamics, biogeography, niche evolution and fruit evolution throughout the last 100 million years that span the evolutionary history of Cyperaceae (MSc 1). Objective 2 is to develop the first genomic resources for Cyperaceae, and to use them to determine how climate influences the frequency of hybridization and introgression. Two Carex genomes will be assembled to chromosome-scale (PhD 1) at low cost from an experimental hybrid, which will allow estimation of the timing and intensity of ancient introgression events, based on the lengths of introgressed genomic blocks. We will also expand on our previous investigations of host-parasite interactions in Cyperaceae by utilizing Anthracoidea fungi, which preferentially parasitize hybrids, as a proxy to infer the frequency of hybridization in deep time (Msc 2). Objective 3 will be to accelerate taxonomic research on the Freshwater Tidal Flora, a rich but threatened North American centre of endemism. Through parallel taxonomic and population genomic studies of two Cyperaceae (BSc 2, MSc 3) and one Asteraceae (PhD 2) lineage endemic to this Flora, we will discover shared patterns of genetic diversity that can be used to prioritize conservation on the most distinct populations and areas. We will then assemble a complete distribution database of all taxa occurring in the Freshwater Tidal Flora (c. 100 species; BSc 3) to test how area, climatic conditions and distance between estuaries affect endemicity, richness, phylogenetic diversity, and population genetic diversity (PhD 2). This combined approach will allow us to discover large-scale historical and ecological processes that shape diversity at all levels of biological complexity, from genes to species and whole communities.