Terrestrial species adapted to sea dispersal: differences in propagule dispersal of two Caribbean mangroves

A central goal of comparative phylogeography is to understand how species-specific traits interact with geomorphological history to govern the geographic distribution of genetic variation within species. One key biotic trait with an immense impact on the spatial patterns of intraspecific genetic differentiation is dispersal. Here we quantify how species-specific traits directly related to dispersal affect genetic variation in terrestrial organisms with adaptations for dispersal by sea, not land—the mangroves of the Caribbean. We investigate the phylogeography of white mangroves (Laguncularia racemosa, Combretaceae) and red mangroves (Rhizophora mangle, Rhizophoraceae) using chloroplast genomes and nuclear markers (thousands of RAD-Seq loci) from individuals throughout the Caribbean. Both coastal tree species have viviparous propagules that can float in salt water for months, meaning they are capable of dispersing long distances. Spatially explicit tests of the role of ocean current...

比较亲缘地理学（comparative phylogeography）的核心目标，是阐明物种特异性性状与地貌历史如何相互作用，进而调控物种种内遗传变异的地理分布格局。对种内遗传分化空间格局具有显著影响的关键生物性状之一为扩散。本研究聚焦于适应海洋而非陆地扩散的陆生生物——加勒比海红树林，量化了与扩散直接相关的物种特异性性状对其遗传变异的影响。我们依托遍布加勒比海区域的采样个体的叶绿体基因组（chloroplast genomes）与核标记（nuclear markers，数千个RAD-Seq位点），对白红树（Laguncularia racemosa，使君子科Combretaceae）和红树（Rhizophora mangle，红树科Rhizophoraceae）的亲缘地理学展开研究。这两种海岸树种均具有胎生繁殖体（viviparous propagules），可在咸水中漂浮数月之久，因此具备长距离扩散的能力。针对洋流作用的空间显式检验……