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

对物种多样性的准确界定和估计是许多生物学领域的关键方面，包括生物地理学、生态学和保护。这项研究的重点是提高我们对地中海盆地物种多样性的理解--地中海盆地是世界上生物多样性最丰富的地区之一。随着对生物多样性的威胁不断增加，主要是由于气候变化和人类压力，准确的评估对于保护工作越来越重要。为了研究精细规模的进化和生物地理模式和过程，研究人员确定了一组鲜为人知的风铃花(风铃属物种复合体)，可以作为理解这一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这类植物的进化史，并提供对物种多样性的准确评估。研究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可能对未来气候变化的反应具有重要意义。研究人员将使用下一代测序方法，包括在广泛分布的风铃和狭隘的地方性风铃种群中有针对性地丰富许多核基因座。虽然测序将集中在风铃属物种复合体上，但核探测器组的设计将使其适用于风铃草科(2400多个分类群)。这种有针对性的测序技术，结合形态数据，以及最近的联合和基于模型的方法，将作为未来研究的模型，整合传统的系统和基因组水平的数据，以评估物种边界和检测维管植物中的隐蔽物种形成。在这项研究过程中开发的探测器集将提供给科学界，促进未来家庭内的进化研究。在系统发育和生物地理框架内研究风铃属复合体，将有助于阐明物种多样性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、地质历史和气候波动等因素联系起来。关于这些分类群，将检验三个假设：i)风铃属聚合体中存在神秘的分类多样性；ii)历史海平面变化促成了异地物种形成；iii)多倍体(基因组复制)一直是该类群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。在这个生物多样性热点地区，对这些进化过程的理解将特别关键，预计保护工作最具挑战性，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.