BIS 2B Lecture Notes - Lecture 17: Anagenesis, Cladogenesis, Phylogenetic Tree

• School: UC-Davis
• Department: Biological Sciences
• Course: BIS 2B
• Professor: Mark Schwartz; Sharon Strauss

Document Summary

Anagenesis - (put that words roots to good use) "the act of up/back/again producing" / one path of changing form, within-lineage change. Nat select + random processes (mutation, gene drift), etc. cladogenesis - "the act of branching production" / the splitting of a lineage to become different lineages via speciation common ancestor = root splits in the branches = node. At the end of nodes = clade. A mutation can make one different than another and less likely to mate, but not typically if mutation is common, mating is easier = higher fitness, and vice versa. We need barrier to gene flow so that pops can diverge through selection and/or drift (anagenesis cladogenesis) Extinction - the disappearance of a lineage. Phylogenetic tree (phylogeny) - graph of history of relationships among group of organisms. Monophyletic clade (good): taxon group that includes all taxa/species descended from a specific common ancestor. Paraphyletic clade (not good): excludes some descendants.