MODELING STABILIZING SELECTION: EXPANDING THE ORNSTEIN-UHLENBECK MODEL OF ADAPTIVE EVOLUTION
MODELING STABILIZING SELECTION: EXPANDING THE ORNSTEIN-UHLENBECK MODEL OF ADAPTIVE EVOLUTION
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DOI：
10.1111/j.1558-5646.2012.01619.x
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发表时间：
2012-08-01
期刊：
影响因子：
3.3
通讯作者：
O'Meara, Brian C.
中科院分区：
文献类型：
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作者：
Beaulieu, Jeremy M.;Jhwueng, Dwueng-Chwuan;O'Meara, Brian C.
比较方法用于研究连续性状的进化变化模式，从布朗运动过程到假设性状根据OrnsteinUhlenbeck（OrnsteinUhlenbeck）过程进化的模型。尽管这些模型在各种情况下都很有用，但它们仍然没有涵盖生物学家想要研究的所有场景。对于基于随机过程的模型，通过假设随机运动的速率和选择的强度在选择性制度之间不变化，在当前的实现中限制了模型的复杂性。在这里，我们扩展了自适应进化的ESTA模型，包括模型，不同地放松了一个恒定的速度和强度的选择的假设。在其最一般的形式中，这里描述的方法可以为每个选择方案分配一个单独的性状最佳值，随机运动参数的速率和选择强度的参数。我们使用模拟来证明我们的模型可以检测到进化过程中有意义的差异，特别是在样本量较大的情况下。我们还说明了我们的方法，使用一个经验的例子，基因组大小的进化在一个大的开花植物分支。
Comparative methods used to study patterns of evolutionary change in a continuous trait on a phylogeny range from Brownian motion processes to models where the trait is assumed to evolve according to an OrnsteinUhlenbeck (OU) process. Although these models have proved useful in a variety of contexts, they still do not cover all the scenarios biologists want to examine. For models based on the OU process, model complexity is restricted in current implementations by assuming that the rate of stochastic motion and the strength of selection do not vary among selective regimes. Here, we expand the OU model of adaptive evolution to include models that variously relax the assumption of a constant rate and strength of selection. In its most general form, the methods described here can assign each selective regime a separate trait optimum, a rate of stochastic motion parameter, and a parameter for the strength of selection. We use simulations to show that our models can detect meaningful differences in the evolutionary process, especially with larger sample sizes. We also illustrate our method using an empirical example of genome size evolution within a large flowering plant clade.