1991/02/01 by Chung‐I Wu · 1 citation
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Mathematics · #Genomics and Phylogenetic Studies #Genetic diversity and population structure #Chromosomal and Genetic Variations #Biology #Phylogenetics #Phylogenetic tree #Evolutionary biology #Null hypothesis #Genetic algorithm #Likelihood-ratio test #Null model #Null (SQL) #Genetics #Statistics #Gene #Mathematics #Ecology
paper · pdf · doi:10.1093/genetics/127.2.429
openalex publication_date 1991/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
Standard formulas of gene frequency change under genetic drift are used to derive the probability of obtaining incorrect phylogenetic information for three species due to segregation of ancient polymorphisms. This probability depends upon the level of polymorphisms at the time of speciation and is generally quite high unless the two speciation events are far apart in time. If phylogenetic data from multiple loci are available, a likelihood ratio test can be used to reject the null hypothesis in favor of the best phylogeny. The appropriate null hypothesis is either a trichotomy or an alternative phylogeny, depending on the data set. The likelihood ratios required for accepting the best phylogeny are given. These ratios are obtained by exact enumeration when the number of loci is small (n less than 15) and by an asymptotic approach for larger n's. In general, more than five loci are needed to resolve the species phylogeny.