BCH447H1 Study Guide - Genetic Drift, Molecular Evolution, Neutral Mutation
Document Summary
Avoid thinking of evolution as a great chain of being or a ladder of progress. There is no such thing as a higher eukaryote. All eukaryotes have evolved for the same length of time. Paramecium is as modern and evolved as tigers. With the explosion in molecular evolution we have more data allowing us to create deep phylogeny. A new form of tree thinking arose in the 1970s. A clade is a group of organisms that share a common ancestor. The tree thinking based on clades is called cladystics. Today they believe that taxonomy of organisms should correspond to their evolutionary relationship. Cladystics says that organisms should be grouped and renamed according to their evolutionary relationships. A tree of all life with luca at the bottom which would define one common ancestor. Now, people are introducing the concept that there is no tree of life.