Data from: Species selection and the macroevolution of coral coloniality and photosymbiosis

Differences in the relative diversification rates of species with variant traits is known as species selection. Species selection can produce a macroevolutionary change in the frequencies of traits by changing the relative number of species possessing each trait over time. But species selection is not the only process that can change the frequencies of traits, phyletic microevolution of traits within species and phylogenetic trait evolution among species, the tempo and mode of microevolution, can also change trait frequencies. Species selection, phylogenetic, and phyletic processes can all contribute to large-scale trends, reinforcing or canceling each other out. Even more complex interactions among macroevolutionary processes are possible when multiple covarying traits are involved. Here I present a multilevel macroevolutionary framework that is useful for understanding how macroevolutionary processes interact. It is useful for empirical studies using fossils, molecular phylogenies, or both. I illustrate the framework with the macroevolution of coloniality and photosymbiosis in scleractinian corals using a time-calibrated molecular phylogeny. I find that standing phylogenetic variation in coloniality and photosymbiosis deflects the direction of macroevolution from the vector of species selection. Variation in these traits constrains species selection and results in a 200 million-year macroevolutionary equilibrium.

具有变异性状的物种间相对多样化速率的差异，被称为物种选择（species selection）。物种选择可通过随时间推移改变携带各性状的物种相对数量，引发性状频率的宏进化（macroevolution）改变。但物种选择并非唯一可改变性状频率的过程：物种内的线系微进化（microevolution）、物种间的系统发育性状进化，以及微进化的速率与模式，同样可改变性状频率。物种选择、系统发育过程与线系过程均可推动宏观演化趋势的形成，彼此间可产生强化或抵消效应。当涉及多个协同变异的性状时，宏进化过程间还可能产生更为复杂的相互作用。本文提出了一个多级宏进化框架，可用于解析宏进化过程间的相互作用机制。该框架适用于利用化石、分子系统发育（molecular phylogenies）数据，或二者结合开展的实证研究。本文以时间校准的分子系统发育树（time-calibrated molecular phylogeny）为基础，以石珊瑚目珊瑚（scleractinian corals）的群体生活（coloniality）与光合共生（photosymbiosis）的宏进化为例，对该框架进行了演示。研究发现，群体生活与光合共生的现存系统发育变异，会使宏进化方向偏离物种选择的作用向量。这些性状的变异会约束物种选择，并最终形成持续2亿年的宏进化平衡状态。