Stochastic Character Mapping of State-Dependent Diversification Reveals the Tempo of Evolutionary Decline in Self-Compatible Onagraceae Lineages
Stochastic Character Mapping of State-Dependent Diversification Reveals the Tempo of Evolutionary Decline in Self-Compatible Onagraceae Lineages
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DOI：
10.1093/sysbio/syy078
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发表时间：
2019-05-01
影响因子：
6.5
通讯作者：
Hoehna, Sebastian
中科院分区：
文献类型：
--
作者：
Freyman, William A.;Hoehna, Sebastian
进化生物学的一个主要目标是确定与物种形成和灭绝率变化相对应的关键进化转变。随机字符映射已成为用来推断的时间，性质和数量的字符状态转换沿着分支的一个遗传学的主要方法。该方法被广泛用于字符进化的标准替代模型。然而，目前的方法不能用于模型，专门测试字符状态转换与多样化率的变化，如状态依赖的物种形成和灭绝（SSE）模型的关联。在这里，我们介绍了一种新的随机字符映射算法，克服了这些限制，并将其应用于研究交配系统的进化在一个时间校准的系统发育的植物科柳叶菜科。利用隐藏状态SSE模型，我们测试了关联的损失自交不亲和性（SI）与多样化率的变化。我们发现，自交亲和的谱系比自交不亲和的谱系有更高的灭绝率和更低的净多样化率。此外，这些结果提供了经验证据的“衰老”多样化率预测在高度自交谱系：我们映射的字符历史表明，SI的损失是由短期spike在物种形成率，下降后的时间滞后几百万年，导致负净多样化。长期以来一直自我兼容的血统，如Fuchsia和Clarkia，正处于以前未被认识的持续进化衰退中。我们的研究结果表明，随机字符映射的SSE模型是一个强大的工具，用于检查的时间和性质的字符状态转换和变化的多样化率在整个生育期。
A major goal of evolutionary biology is to identify key evolutionary transitions that correspond with shifts in speciation and extinction rates. Stochastic character mapping has become the primary method used to infer the timing, nature, and number of character state transitions along the branches of a phylogeny. The method is widely employed for standard substitution models of character evolution. However, current approaches cannot be used for models that specifically test the association of character state transitions with shifts in diversification rates such as state-dependent speciation and extinction (SSE) models. Herein, we introduce a new stochastic character mapping algorithm that overcomes these limitations, and apply it to study mating system evolution over a time-calibrated phylogeny of the plant family Onagraceae. Utilizing a hidden state SSE model we tested the association of the loss of self-incompatibility (SI) with shifts in diversification rates. We found that self-compatible lineages have higher extinction rates and lower net-diversification rates compared with self-incompatible lineages. Furthermore, these results provide empirical evidence for the "senescing" diversification rates predicted in highly selfing lineages: our mapped character histories show that the loss of SI is followed by a short-termspike in speciation rates, which declines after a time lag of severalmillion years resulting in negative net-diversification. Lineages that have long been self-compatible, such as Fuchsia and Clarkia, are in a previously unrecognized and ongoing evolutionary decline. Our results demonstrate that stochastic character mapping of SSE models is a powerful tool for examining the timing and nature of both character state transitions and shifts in diversification rates over the phylogeny.