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arXiv 0905.4542q-bio.PE
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从过滤数据估计树木:形态系统发生模型的可识别性

Estimating Trees from Filtered Data: Identifiability of Models for Morphological Phylogenetics

Elizabeth S. Allman, Mark T. Holder, John A. Rhodes

摘要:

作为简约性分析的替代,已经提出了随机模型(Lewis,2001),(Nylander等人,2004)的形态特征,使最大似然或贝叶斯分析可用于系统发育推断。这些模型的一个关键特征是它们考虑了确定偏差,因为只观察到变化的或简约的信息特征。然而,这种基于模型的推断的统计一致性要求模型参数可以从它们所需要的联合分布中识别,并且这个问题尚未得到解决。在这里,我们证明了几个这样的模型,具有任意大小的有限状态空间的参数,是可识别的,只要树至少有8叶。如果树的拓扑结构是已知的,那么7个叶子就足够用于数值参数的可识别性。证明的方法涉及到首先推断一个完整的分布的简约信息和非信息模式的联合概率从简约信息的,使用系统发育不变量。本文还研究了4分类元树的树参数的可识别性失效问题。

英文摘要:

As an alternative to parsimony analyses, stochastic models have been proposed (Lewis, 2001), (Nylander, et al., 2004) for morphological characters, so that maximum likelihood or Bayesian analyses may be used for phylogenetic inference. A key feature of these models is that they account for ascertainment bias, in that only varying, or parsimony-informative characters are observed. However, statistical consistency of such model-based inference requires that the model parameters be identifiable from the joint distribution they entail, and this issue has not been addressed. Here we prove that parameters for several such models, with finite state spaces of arbitrary size, are identifiable, provided the tree has at least 8 leaves. If the tree topology is already known, then 7 leaves suffice for identifiability of the numerical parameters. The method of proof involves first inferring a full distribution of both parsimony-informative and non-informative pattern joint probabilities from the parsimony-informative ones, using phylogenetic invariants. The failure of identifiability of the tree parameter for 4-taxon trees is also investigated.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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