Is there a star tree paradox?
Is there a star tree paradox?
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是否存在星树悖论？
DOI：
10.1093/molbev/msl059
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发表时间：
2006
影响因子：
10.7
通讯作者：
Thornton,JosephW
中科院分区：
文献类型：
--
作者：
Kolaczkowski,Bryan;Thornton,JosephW
有人担心，当真正的树未解析或具有非常短的内部分支时，系统发育树上的后验概率可能是不可靠的，因为现有的贝叶斯系统发育分析方法不明确地评估未解析的树。最近的两篇论文提出，只评估已解析树会导致“星树悖论”：当真正的树未解析或接近它时，随着序列长度的增长，后验概率预计将变得越来越不可预测，导致对一棵或另一棵已解析树的置信度膨胀，并增加错误阳性推断的风险。在这里，我们表明情况并非如此；现有的贝叶斯方法不会导致统计置信度的膨胀，只要进化模型是正确的，并且假设没有信息的先验。后验概率不会随着序列长度的增加而变得越来越不可预测，并且它们表现出保守的I型错误率，从而导致低的假阳性推论。对于无限的数据，后验概率对所有解析的树给予相同的支持，并且错误推论的比率降为零。我们的结论是，不存在因不抽样未分解的树木而引起的星树悖论。
Concerns have been raised that posterior probabilities on phylogenetic trees can be unreliable when the true tree is unresolved or has very short internal branches, because existing methods for Bayesian phylogenetic analysis do not explicitly evaluate unresolved trees. Two recent papers have proposed that evaluating only resolved trees results in a “star tree paradox”: when the true tree is unresolved or close to it, posterior probabilities were predicted to become increasingly unpredictable as sequence length grows, resulting in inflated confidence in one resolved tree or another and an increasing risk of false-positive inferences. Here we show that this is not the case; existing Bayesian methods do not lead to an inflation of statistical confidence, provided the evolutionary model is correct and uninformative priors are assumed. Posterior probabilities do not become increasingly unpredictable with increasing sequence length, and they exhibit conservative type I error rates, leading to a low rate of false-positive inferences. With infinite data, posterior probabilities give equal support for all resolved trees, and the rate of false inferences falls to zero. We conclude that there is no star tree paradox caused by not sampling unresolved trees.