More than half of reef-building corals (Scleractinia) participate in a nutritional symbiosis, known as photosymbiosis, with photosynthetic dinoflagellates that ranges from obligate to facultative dependence. Fitting hidden-rates models allowing among-lineage variation in the rate of trait evolution to supertree and molecular phylogenies of Scleractinia, we reconstruct the history of photosymbiosis within Scleractinia and characterize its evolutionary stability. We find that most lineages of scleractinians are extraordinarily stable for the trait, evincing no instances of loss, but that in some clades photosymbiosis is more labile, thus providing a framework for comparative studies to further our mechanistic understanding of the factors that shape the evolutionary fates of scleractinian photosymbiosis.

中文翻译：

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珊瑚光共生进化稳定性的谱系特异性变异

超过一半的造礁珊瑚（Scleractinia）参与营养共生，称为光共生，光合甲藻从专性依赖到兼性依赖不等。拟合隐藏速率模型，允许性状进化速率的谱系间变异与 Scleractinia 的超级树和分子系统发育，我们重建了 Scleractinia 内光共生的历史并表征其进化稳定性。我们发现大多数 scleractinians 谱系的特征非常稳定，没有证据表明损失，但在某些进化枝中，光共生更加不稳定，因此为比较研究提供了一个框架，以进一步我们对影响进化命运的因素的机械理解菌核光共生。