Biology 3466B Lecture Notes - Lecture 7: Upgma, Maximum Likelihood Estimation, Chromosome
18 Oct 2012
School
Department
Course
Professor
Document Summary
Principles of phylogenetic: observation: all species are related by a common ancestry, observation: implication: a classification based on evolutionary history will be informative and permanent. As species change through time (anagenesis) differences accumulate within species. As species spilt (cladogensis) differences accumulate between species: application the current character states can be used to reconstruct that history in a phylogenetic classification taxa should be monophyletic, monophyletic: derived from single lineages. Reptiles without birds are paraphyletic: a subset of lineages with members excluded (a group that contains some taxa that are related but some that are not) Cold blooded tetra pods would be polyphyletic: made up of selected taxa from diverse lineages (doesn"t follow that high achy. E. g. having warm blood shared by mammals and birds not due to common genetic basis but because it evolved twice in evolutionary time. Convergent occurs when natural selection favours similar structures as solutions to problems posed by similar environments.
