Data from: Coordinated dispersal and pre-Isthmian assembly of the Central American ichthyofauna

We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in Lagrange+, a modified version of the ML-based parametric biogeographic program Lagrange. DO is measured in units of ‘wallaces’ (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto-Orinoco-Amazon (POA) river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America (GACA) during the Paleocene-Eocene (c. 58-45 Ma), potentially during the existence of an incomplete Paleogene Arc (~59 Ma) or Lesser Antilles Arc (~45 Ma), but predating the GAARlandia land bridge (~34-33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) plate margin did not serve as a dispersal corridor until the Late Neogene (12-0 Ma), and contributed relatively little to the formation of modern distributions.

本研究记录了加勒比盆地物种多样性最高的两个淡水鱼支系——Heroine慈鲷（heroine cichlids）与花鳉亚科胎生鱼类（poeciliine live-bearers）在演化时间尺度上的协同扩散模式。观测扩散速率（Observed dispersal rate, DO）的数值通过时间校准分子系统发育树估算得到，所用工具为Lagrange+——一款基于最大似然法的参数化生物地理学程序Lagrange的改良版本。DO以"华莱士单位（wallaces，缩写wa）"为单位，定义为每百万年发生的生物地理分布扩张事件数量。本次DO估算基于晚白垩世至今的三个时间区间内的五区域动态古地理景观开展。预期扩散速率（Expected dispersal rate, DE）的数值则通过多种备选古地理模型生成，其扩散速率与目标区域面积、源河径流量呈正相关，与古地理距离呈负相关。本研究通过DO与DE之间的相关性，评估了上述三类生物地理学参数的相对贡献。DO估算结果显示，在盛行且常年存在的河流径流水动力载体（如原奥里诺科-亚马逊河（Proto-Orinoco-Amazon, POA））的影响下，加勒比板块东部（安的列斯）边缘存在持续的扩散廊道。祖先区域重建结果表明，大安的列斯群岛与中美洲（Greater Antilles and Central America, GACA）的最早殖民事件发生于古新世-始新世（约5800万至4500万年前），可能对应未完全形成的古近纪弧（约59 Ma）或小安的列斯弧（约45 Ma）存在的时期，但早于GAARlandia陆桥（约3400万至3300万年前）的形成时间。古地理距离是DO的最佳单一预测因子。直至晚新近纪（1200万年前至今），加勒比板块西部（中美洲）边缘才成为扩散廊道，且其对现代鱼类分布格局的形成贡献相对有限。