Niche evolution during allopatric and sympatric diversification of Aeonium (Crassulaceae) on the Canary Islands

Although species radiations on island archipelagos are broadly studied, the geographic and ecological modes of speciation that underlie diversification are often not fully understood. Both allopatry and sympatry play a role during radiations, particularly on islands with profound habitat diversity. Here, we use the most diverse Canary Island plant radiation, Aeonium (Crassulaceae), to phylogenetically test two hypotheses: (1) allopatric speciation, which predicts that closely related taxa are ecologically similar but do not co-occur, and (2) sympatric speciation, whereby closely related taxa co-occur geographically but are ecologically distinct. We fitted niche and spatial distribution models based on extensive field surveys to quantify geographic and ecological divergence among taxa integrated in a phylogenetic context. Contrary to our expectation, phylogenetically closely related species tend to occupy similar ecological niches, revealing that ecological niche divergence among species..., We surveyed the archipelago, covering all 38 Aeonium species and subspecies following Bañares-Baudet (2015). Surveys were performed between February and September in 2018–2020 and aimed at capturing the ecological breadth of the islands through high-resolution presence/absence observation points. To guarantee a dense and stratified sampling, we divided each sampled island into climatic quarters based on the average of the mean annual temperature (bio01) and annual precipitation (bio12): 1) dry and hot; 2) dry and cold; 3) wet and hot; 4) wet and cold. The quarters of each island were sampled through extensive driving and hiking. A total of 10’180 data points were collected using a Global Positioning System receiver (GPS 72H, Garmin, Taiwan) with a positional accuracy of ~ 5 m, including 9’719 presences (including data points with multi-taxa occurrences) and 2’450 absences. Points were registered at c. 50 – 200 m intervals, noting all occurring Aeonium species. For each island, we observ..., , # Spatial dataset with presences and absences of the Aeonium genus (Crassulaceae) from the Canary Islands [https://doi.org/10.5061/dryad.3bk3j9krt](https://doi.org/10.5061/dryad.3bk3j9krt) The Dataset includes field-collected presences and absences for 38 taxa (species and subspecies) of *Aeonium* (Crassulaceae). The surveys on the Canary Islands include the islands of El Hierro, Gran Canaria, Lanzarote, La Gomera, La Palma, and Tenerife. ## Description of the data and file structure The dataset has 43 columns, including \"ID\" (a unique value that identifies the spatial point), \"sur\" (the origin of the points, numbers 1-4 indicate different field surveys), \"lon\" (longitude), \"lat\" (latitude), \"p_a\" (indicates presence or absence: \"a\" is absence, \"p\" is field collected presence which can include multiple co-occurring taxa, \"fp\" indicates presences collected from public datasets), \"aiz\" to \"vol\" indicate the 38 taxa, on each point \"0\" indicates absence and \"1\" indicates a presence. So...尽管岛屿群岛上的物种辐射演化已得到广泛研究，但支撑物种多样化的地理与生态成种模式往往尚未被完全阐明。异地成种（allopatry）与同地成种（sympatry）在辐射演化过程中均发挥作用，尤其在生境多样性极高的岛屿上。本研究以加那利群岛物种多样性最高的植物辐射演化类群——莲花掌属（Aeonium，景天科Crassulaceae）为研究对象，从系统发育角度检验两个假说：（1）异地成种假说（allopatric speciation），该假说预测亲缘关系相近的类群生态位相似但地理分布不重叠；（2）同地成种假说（sympatric speciation），即亲缘关系相近的类群地理分布重叠但生态位分化显著。我们基于大规模野外调查数据构建生态位与空间分布模型，以量化系统发育框架下类群间的地理与生态分化。与我们的预期相反，系统发育关系紧密的物种往往占据相似的生态位，这表明物种间的生态位分化…… 我们调查了整个群岛，按照Bañares-Baudet（2015）的分类标准涵盖了全部38个莲花掌属（Aeonium）物种及亚种。野外调查于2018–2020年的2月至9月间开展，旨在通过高分辨率的存在/缺失观测点全面记录群岛的生境分布范围。为保证采样密集且分层合理，我们根据年平均气温（bio01）与年降水量（bio12）的平均值将每个调查岛屿划分为4个气候区：1）干热型；2）干冷型；3）湿热型；4）湿冷型。通过大规模驾车与徒步采样的方式对每个岛屿的各气候区进行调查。共采集到10180个数据点，使用定位精度约5米的全球定位系统接收机（GPS 72H，佳明Garmin，中国台湾）完成采集，其中包括9719个存在点（包含多类群共存的数据点）与2450个缺失点。采样点以约50–200米的间距布设，并记录所有出现的莲花掌属（Aeonium）物种。针对每个岛屿，我们观测…… # 加那利群岛莲花掌属（Aeonium，景天科Crassulaceae）物种存在与缺失空间数据集 [https://doi.org/10.5061/dryad.3bk3j9krt] 本数据集包含野外采集的景天科莲花掌属（Aeonium）38个类群（物种及亚种）的存在与缺失数据。 加那利群岛的调查覆盖了耶罗岛（El Hierro）、大加纳利岛（Gran Canaria）、兰萨罗特岛（Lanzarote）、拉戈梅拉岛（La Gomera）、拉帕尔马岛（La Palma）与特内里费岛（Tenerife）。 ## 数据与文件结构说明 本数据集共包含43列字段，具体如下："ID"为识别空间点位的唯一标识；"sur"代表数据点来源，数字1-4分别对应4次不同的野外调查；"lon"为经度，"lat"为纬度；"p_a"用于标记点位的存在/缺失状态："a"表示缺失，"p"表示野外采集的存在点（可包含多个共存类群），"fp"表示从公共数据集获取的存在点；"aiz"至"vol"对应38个类群，每个点位的对应字段中"0"代表该类群未出现，"1"代表该类群存在。 综上，