BSCI 207 Lecture Notes - Lecture 2: Conservation Biology, Paraphyly, Ratite
26 Jan 2016
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Document Summary
Bsci207 - lecture 2 - interpreting phylogenetic trees and tracing the evolution of traits. Inference of patterns of evolutionary relationships (shared ancestors) based on the distribution of character states in the organism being studied. Genes (and other dna) in organisms are copied to the next generation with errors/changes. Understanding evolution, epidemiology and forensics, conservation biology. A phylogenetic tree visually displays relationships among the organisms being studied. Cladogram branch lengths are not meaningful (tells you relationships) Each node in the tree represents the divergence of one lineage into two sister lineages. 2 sister lineages share a most recent common ancestor. Branches can be rotated without changing relationships. All the organisms at the tips have the same amount of evolutionary history (one did not evolve from another) A living species can"t be primitive character states (features) can be. Organisms are mosaics of primitive and derived (newly arisen) character states. Marsupials: young derived mainly in mom"s pouch.
