DISSERTATION RESEARCH: Integrating Biogeography, Cytology, Niche Modeling and Phylogenetics to Understand the Evolutionary History of Endemic Campanula Species in the Mediterranean

物种多样性的准确界定和估计是许多生物学领域（包括生物地理学、生态学和保护）的关键方面。这项研究的重点是提高我们对地中海盆地物种多样性的了解——地中海盆地是世界上生物多样性最丰富的地区之一。由于气候变化和人类压力，生物多样性面临的威胁日益加剧，准确的评估对于保护工作变得越来越重要。为了研究精细尺度的进化和生物地理模式和过程，研究人员发现了一个人们知之甚少的风铃草群体（风铃草物种复合体），它可以作为了解这个高度多样化地区进化驱动因素的模型。该项目将特别侧重于推断进化历史并提供对这组植物物种多样性的准确评估。结果将对了解地中海生物多样性的起源、设计成功的保护工作以及预测对未来气候变化的可能应对措施产生重要影响。研究人员将采用下一代测序方法，包括对广泛分布的风铃草和狭窄的特有风铃草种群中的众多核位点进行有针对性的富集。虽然测序将集中于风铃草物种复合体，但核探针组的设计将使其适用于风铃科（超过 2400 个分类单元）。这种靶向测序技术与形态学数据以及最近的聚结和基于模型的方法相结合，将作为未来研究的模型，整合传统的系统和基因组水平数据，以评估物种边界和检测维管植物中的神秘物种形成。在这项研究过程中开发的探针组将提供给科学界，以促进未来的家庭进化研究。在系统发育和生物地理学框架中研究风铃复合体将阐明物种多样化和持久性的驱动因素，并使研究人员能够将这些机制与生态学、地质历史和气候波动等因素联系起来。关于这些分类群，将测试三个假设： i) 风铃草聚集体中存在隐秘的分类多样性； ii) 历史海平面变化导致异域物种形成； iii) 多倍体（基因组重复）一直是该群体中的一个重要历史因素，多倍体可能代表与其二倍体祖先不同的物种。了解这些进化过程对于这个生物多样性热点地区尤其重要，因为这里的保护工作预计最具挑战性，但可能会带来最高的回报。

Accurate delimitations and estimates of species diversity are critical aspects for many areas of biology, including biogeography, ecology, and conservation. This research focuses on improving our understanding of species diversity in the Mediterranean Basin - one of the most biologically diverse areas in the world. As threats to biodiversity mount, due mainly to climate change and human pressure, accurate assessments are increasingly important for conservation efforts. To study fine-scale evolution and biogeographic patterns and processes, the researchers have identified a poorly understood group of bellflowers (the Campanula erinus species complex) that can serve as a model for understanding the drivers of evolution in this highly diverse area. This project will focus specifically on inferring the evolutionary history and providing an accurate assessment of species diversity in this group of plants. Results will have important implications for understanding the origins of Mediterranean biodiversity, designing successful conservation efforts, and anticipating possible responses to future climate change.The researchers will employ a next-generation sequencing approach, involving targeted enrichment of numerous nuclear loci across populations of both the widespread Campanula erinus and the narrow endemic, Campanula creutzburgii. Though sequencing will focus on the Campanula erinus species complex, the nuclear probe set will be designed such that it will be useful across the Campanulaceae (more than 2400 taxa). This targeted sequencing technique, in conjunction with morphological data, and recent coalescent and model-based methods, will serve as a model for future studies integrating traditional systematic and genome-level data for evaluating species boundaries and detecting cryptic speciation in vascular plants. The probe set developed during the course of this study will be made available to the scientific community, facilitating future evolutionary studies within the family. Studying the Campanula erinus complex in a phylogenetic and biogeographic framework will illuminate the drivers of diversification and persistence of species and allow the researchers to relate these mechanisms to factors such as ecology, geologic history, and climatic fluctuations. Three hypotheses will be tested regarding these taxa: i) Cryptic taxonomic diversity is present within the Campanula erinus aggregate; ii) Historical sea level changes contributed to allopatric speciation; iii) Polyploidy (genome duplication) has been an important historical factor in this group and polyploids may represent species distinct from their diploid progenitors. An understanding of these evolutionary processes will be especially critical in this biodiversity hotspot, where conservation efforts are expected to be most challenging but likely give the highest payoff.