title: Phylogenetic test of the molecular clock and linearized trees.
abstract: To estimate approximate divergence times of species or species groups with molecular data, we have developed a method of constructing a linearized tree under the assumption of a molecular clock. We present two tests of the molecular clock for a given topology: two-cluster test and branch-length test. The two-cluster test examines the hypothesis of the molecular clock for the two lineages created by an interior node of the tree, whereas the branch-length test examines the deviation of the branch length between the tree root and a tip from the average length. Sequences evolving excessively fast or slow at a high significance level may be eliminated. A linearized tree will then be constructed for a given topology for the remaining sequences under the assumption of rate constancy. We have used these methods to analyze hominoid mitochondrial DNA and drosophilid Adh gene sequences.
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics; D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000235:genetics; D003663:Decision Trees; D004330:Drosophila / Q000235:genetics; D017344:Genes, Insect; D006071:Gorilla gorilla / Q000235:genetics; D015186:Hominidae / Q000235:genetics; D006801:Humans; D008433:Mathematics; D008958:Models, Molecular; D002679:Pan troglodytes / Q000235:genetics; D010802:Phylogeny; D011148:Pongo pygmaeus / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D000426:Alcohol Dehydrogenase