Vitales Daniel, Guerrero Carmen, Garnatje Teresa, Romeiras Maria M, Santos Arnoldo, Fernandes Francisco, Vallès Joan
Institut Botànic de Barcelona (IBB), CSIC-Ajuntament de Barcelona, Passeig del Migdia s/n, 08038 Barcelona, Catalonia, Spain.
Laboratori de Botànica (UB), Unitat Associada al CSIC, Facultat de Farmàcia i Ciències de l'Alimentació-Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain.
AoB Plants. 2023 Aug 14;15(4):plad057. doi: 10.1093/aobpla/plad057. eCollection 2023 Jul.
Anagenetic speciation is an important mode of evolution in oceanic islands, yet relatively understudied compared to adaptive radiation. In the Macaronesian region, three closely related species of (i.e. , and ) are each endemic from a single archipelago (i.e. Madeira, Canary Islands and Cape Verde, respectively), representing a perfect opportunity to study three similar but independent anagenetic speciation processes. By analysing plastid and nuclear DNA sequences, as well as nuclear DNA amount data, generated from a comprehensive sampling in all the islands and archipelagos where these species are currently distributed, we intend to find common evolutionary patterns that help us explain the limited taxonomic diversification experienced by endemic Macaronesian . Our time-calibrated phylogenetic reconstruction suggested that divergence among the three lineages occurred in a coincidental short period of time during the Pleistocene. Haplotype and genetic differentiation analyses showed similar diversity values among , and . Clear phylogeographic patterns-showing comparable genetic structuring among groups of islands-were also found within the three archipelagos. Even from the cytogenetic point of view, the three species presented similarly lower genome size values compared to the mainland closely related species . We hypothesize that the limited speciation experienced by the endemic in Madeira, Canary Islands and Cape Verde archipelagos could be related to their recent parallel evolutionary histories as independent lineages, combined with certain shared characteristics of seed dispersal, pollen transport and type of habitat.
前进演化物种形成是海洋岛屿进化的一种重要模式，但与适应性辐射相比，其研究相对较少。在马卡罗尼西亚地区，三种密切相关的[物种名称未给出]（即[具体物种名称1]、[具体物种名称2]和[具体物种名称3]）分别是单一群岛（即分别为马德拉群岛、加那利群岛和佛得角群岛）的特有物种，这代表了一个绝佳的机会来研究三个相似但独立的前进演化物种形成过程。通过分析从这些物种目前分布的所有岛屿和群岛的全面采样中生成的质体和核DNA序列，以及核DNA含量数据，我们旨在找到共同的进化模式，以帮助我们解释马卡罗尼西亚特有[物种名称未给出]所经历的有限分类学多样化。我们的时间校准系统发育重建表明，这三个谱系之间的分歧发生在更新世的一个巧合的短时期内。单倍型和遗传分化分析显示，[具体物种名称1]、[具体物种名称2]和[具体物种名称3]之间具有相似的多样性值。在这三个群岛中也发现了清晰的系统地理模式——显示出各岛屿组之间具有可比的遗传结构。甚至从细胞遗传学的角度来看，与大陆上密切相关的[物种名称未给出]相比，这三个物种的基因组大小值同样较低。我们假设，马德拉群岛、加那利群岛和佛得角群岛的特有[物种名称未给出]所经历的有限物种形成可能与其作为独立谱系的近期平行进化历史有关，再加上种子传播、花粉运输和栖息地类型的某些共同特征。
