Committee on Evolutionary Biology, The University of Chicago 1025 E. 57th Street, Chicago, IL 60637, U.S.A; Science & Education, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605, U.S.A.
Botanischer Garten, Königin-Luise-Straße 6-8, 14195 Berlin, Germany.
Mol Phylogenet Evol. 2023 Sep;186:107830. doi: 10.1016/j.ympev.2023.107830. Epub 2023 May 27.
Phylogenetic approaches to macroevolution have provided unique insight into evolutionary relationships, ancestral ranges, and diversification patterns for many taxa. Similar frameworks have also been developed to assess how environmental and/or spatial variables shape species diversity and distribution patterns at different spatial/temporal scales, but studies implementing these are still scarce for many groups, including lichens. Here, we combine phylogeny-based ancestral range reconstruction and diversification analysis with community phylogenetics to reconstruct evolutionary origins and assess patterns of taxonomic and phylogenetic relatedness between island communities of the lichenized fungal genus Sticta in the Caribbean. Sampling was carried out in the Greater Antilles (Cuba, Jamaica, Dominican Republic, and Puerto Rico) and Lesser Antilles (Dominica, Guadeloupe, and Martinique). Data for six molecular loci were obtained for 64 candidate Caribbean species and used to perform both macroevolutionary phylogenetics, which also included worldwide taxa, and phylobetadiversity analyses, which emphasized island-level communities. Our work uncovered high levels of island endemism (∼59%) in Caribbean Sticta. We estimate initial colonization of the region occurred about 19 Mya from a South American ancestor. Reverse migration events by Caribbean lineages to South America were also inferred. We found no evidence for increased diversification rates associated with range expansion into the Caribbean. Taxonomic and phylogenetic turnover between island-level communities was most strongly correlated with environmental variation rather than with geographic distance. We observed less dissimilarity among communities from the Dominican Republic and Jamaica than between these islands and the Lesser Antilles/Puerto Rico. High levels of hidden diversity and endemism in Caribbean Sticta reaffirm that islands are crucial for the maintenance of global biodiversity of lichenized fungi. Altogether, our findings suggest that strong evolutionary links exist between Caribbean and South American biotas but at regional scales, species assemblages exhibit complex taxonomic and phylogenetic relationships that are determined by local environments and shared evolutionary histories.
系统发育方法为许多分类群提供了有关进化关系、祖先范围和多样化模式的独特见解。类似的框架也被开发出来，以评估环境和/或空间变量如何在不同的时空尺度上塑造物种多样性和分布模式，但对于许多群体，包括地衣，实施这些研究的仍然很少。在这里，我们将基于系统发育的祖先范围重建和多样化分析与群落系统发育学相结合，重建加勒比地衣真菌属 Sticta 的岛屿群落的进化起源，并评估其分类和系统发育相关性模式。采样在大安的列斯群岛（古巴、牙买加、多米尼加共和国和波多黎各）和小安的列斯群岛（多米尼克、瓜德罗普和马提尼克）进行。为 64 种候选加勒比物种获得了六个分子基因座的数据，并用于进行宏观进化系统发育学分析，该分析还包括了全球分类群，以及强调岛屿水平群落的系统发育多样性分析。我们的研究结果揭示了加勒比海 Sticta 具有很高的岛屿特有性（约 59%）。我们估计该地区的初始殖民化发生在大约 1900 万年前，来自南美洲的祖先。还推断出加勒比谱系向南美洲的反向迁移事件。我们没有发现与向加勒比扩张相关的多样化率增加的证据。岛屿水平群落之间的分类和系统发育周转率与环境变化的相关性最强，而与地理距离的相关性最弱。我们发现，多米尼加共和国和牙买加的群落之间的差异比这些岛屿与小安的列斯群岛/波多黎各之间的差异要小。加勒比海 Sticta 中隐藏多样性和特有性的高水平再次证实，岛屿对于维持地衣真菌的全球生物多样性至关重要。总的来说，我们的研究结果表明，加勒比海和南美洲生物区系之间存在着强烈的进化联系，但在区域尺度上，物种组合表现出复杂的分类和系统发育关系，这些关系是由当地环境和共同的进化历史决定的。
