CAS BI 107 Lecture Notes - Lecture 13: Phylogenetics, Convergent Evolution, Ingroups And Outgroups
4 Nov 2016
School
Department
Course
Professor
Document Summary
Descent with modification (natural selection) results in a natural hierarchy of life, a phylogenic tree, or phylogeny. Phylogenetic trees- hypotheses of the hierarchical, evolutionary relationships of organisms, genes of populations. When ancestral lineages divided into descendant lineages. Node- split in branch that indicate a division of one lineage into two. Root- common ancestor for the group, normally shown on left. Note: branches can be flipped around the node without changing the meaning of the tree! Inference: chimps and humans diverged 5 million years ago, while we diverged from gorillas earlier, and orangutans much earlier. Hiv 1 is more harmful to us than hiv 2 because chimpanzees are our closest living relatives! (refer back to phylogeny of primates) In court: phylogenetic evidence supported that man injected former girlfriend with hiv. Girlfriend"s hiv was in the man"s hiv clade, rather than someone"s from the community. Phylogeny can be used to estimate epidemiology, ex. origins of s-oiv epidemic, the current.
