BIOL 150 Lecture Notes - Lecture 1: Background Extinction Rate, Local Extinction, Monophyly
Document Summary
Phylogenetic models of the evolutionary history of organisms, representation that can be used to test the evolutionary history of organisms. He realized that natural selection acting differently in populations would set in motion continuous potential for divergence and speciation, meaning that all organisms are modi cations of ancestral populations! Phylogenetic trees can use many sources of data, such as: Morphological traits (living or fossilized) (dif cult because traits can be deceptive) These data are used to infer an evolutionary history. Root of the tree: oldest part of the tree common ancestor of organisms (taxa, or species) shown at tips; roots are the past, tips are the present. Branches: represent speciation from a common ancestor. Monophyletic groups (clades): are a common ancestor and all of its descendants, and no others. Relatedness: to gure out who is more closely related to whom, compare their common ancestors; those most closely related have a more recent common ancestor.
