The implications of stratigraphic compatibility for character integration among fossil taxa

Two characters are stratigraphically compatible if some phylogenies indicate that their combinations (state-pairs) evolved without homoplasy and in an order consistent with the fossil record. Simulations assuming independent character change indicate that we expect approximately 95% of compatible character pairs to also be stratigraphically compatible over a wide range of sampling regimes and general evolutionary models. However, two general models of rate heterogeneity elevate expected stratigraphic incompatibility: “early burst” models, where rates of change are higher among early members of a clade than among later members of that clade, and “integration” models, where the evolution of characters is correlated in some manner. Both models have important theoretical and methodological implications. Therefore, we examine 259 metazoan clades for deviations from expected stratigraphic compatibility. We do so first assuming independent change with equal rates of character change through ti...

若部分系统发育（phylogenies）研究表明，两个性状的组合（性状对，state-pairs）演化过程中无趋同演化（homoplasy），且演化顺序与化石记录（fossil record）一致，则称这两个性状为地层兼容（stratigraphically compatible）性状。基于性状独立演化假设的模拟实验显示，在多种采样方案（sampling regimes）与通用演化模型（evolutionary models）下，约95%的兼容性状对同时也会是地层兼容的。然而，两类普遍的速率异质性（rate heterogeneity）模型会提升预期的地层不兼容比例：一类是“早爆发”（early burst）模型，即支系（clade）早期类群的演化速率高于后期类群；另一类是“整合”（integration）模型，即不同性状的演化以某种方式存在相关性。这两类模型均具有重要的理论与方法论意义。因此，本研究针对259个后生动物（metazoan）支系，检验其地层兼容性是否偏离预期值。我们首先基于性状演化独立且速率均等的假设开展分析……