EEB362H1 Chapter Notes - Chapter 2-3: Parallel Evolution, Autapomorphy, Synapomorphy
6 Oct 2016
School
Department
Course
Professor
Document Summary
Tutorial 3 chapter 2 & 3 of the complete cladist. Binary characters: ts with only 2 homologous characters are automatically ordered, but not necessarily polarized. Traits shared through common descent (from common ancestor): evolved in same way, equivalent in sister species, inform us of the true state of evolution, include: Only synapomorphy is helpful for creating groups b/c tells us traits unique to group of taxa (ancestors and descendants: the rest don"t give enough info to be useful. These are all types of homoplasious characters. Same character but different evolutionary path (independent evolution: look at tips of trees: Both end as pink but have 2 different processes to get there. Similar character, similar but independent evolutionary path: characters don"t originate in common ancestor, green comes from red ancestor, both evolved in the same way. Character reverts back to ancestral state (character that ancestor has) Character was lost then regained (= character evolved independently) Basic phylogenetic techniques: #1 hennig"s auxiliary principle.
