BLG 144 Chapter Notes - Chapter 27: Phylogenetic Tree, Genetic Distance, Phenetics
Document Summary
Chapter 27 biology study notes: phylogenies and the history of life. Two major analytical tools that biologists use to reconstruct the history of life are phylogenetic trees and the fossil record. Phylogenetic trees- a model that documents the evolutionary relationship of organisms. Fossil record- a record of all the fossils known to man that provide physical evidence of organisms that lived in the past. Adaptive radiations- are instances of rapid diversification that occur because of ecological opportunities and new morphological innovations. Mass extinctions- are environmental catastrophes that rapidly eliminate most species. Phylogeny- the history of a group of organisms. Phylogenies are usually summarized using phylogenetic trees which show the relationship between ancestors and their descendants. Researchers analyze morphological and/or genetic characteristics to create phylogenetic relationships between species. Node (or fork)- the point where the branches diverge and represents the point in time when an ancestral species split into two or more descendant species.
