Phylogenetic mixtures model the inhomogeneous molecular evolution commonly observed in data. The performance of phylogenetic reconstruction methods where the underlying data is generated by a mixture model has stimulated considerable recent debate. Much of the controversy stems from simulations of mixture model data on a given tree topology for which reconstruction algorithms output a tree of a different topology; these findings were held up to show the shortcomings of particular tree reconstruction methods. In so doing, the underlying assumption was that mixture model data on one topology can be distinguished from data evolved on an unmixed tree of another topology given enough data and the ``correct'' method. Here we show that this assumption can be false. For biologists our results imply that, for example, the combined data from two genes whose phylogenetic trees differ only in terms of branch lengths can perfectly fit a tree of a different topology.
An explicit bound is given for the Kolmogorov distance between a mixture of normal distributions and a normal distribution with properly chosen parameter values. A random variable X has a mixture of normal distributions if its conditional distribution given some sigma-algebra is normal. The bound depends only on the first two moments of the first two conditional moments of X given this sigma-algebra. As an application, the Yule-Ornstein-Uhlenbeck model, used in the field of phylogenetic comparative methods, is considered. A bound is derived for the Kolmogorov distance between the distribution …
Modeling Protein Evolution via Generative Inference From Monte Carlo Chains to Population Genetics
Politecnico di Torino(都灵理工大学);Sorbonne Université(索邦大学);CNRS(法国国家科学研究中心);Laboratory of Computational and Quantitative Biology(计算与定量生物学实验室);École Normale Supérieure(巴黎高等师范学院);PSL Université(巴黎文理研究大学);Université de Paris(巴黎大学);The James Franck Institute(詹姆斯·弗兰克研究所);The University of Chicago(芝加哥大学);Department of Physics, The University of Chicago(芝加哥大学物理系);INFN, Sezione di Torino(意大利国家核物理研究所都灵分部);Italian Institute for Genomic Medicine, IRCCS Candiolo(意大利基因组医学研究所坎迪奥洛医院);Dipartimento di Fisica, Sapienza Università di Roma(罗马大学物理系)