BIO 200 Lecture 8: Bio 200 Lecture 8 notes
5 Oct 2016
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Introducing trees and tree terminology: how to make trees from molecular data, parsimony, and if you don"t have molecular data, homology and analogy, putting events on trees, does taxonomy reflect phylogeny, monophyly vs. paraphyly. Branches: diagonal lines: represent genetic change or differences (the further away the more different, nodes: crossing sections. Time runs for the bottom (past) to the top (present: tips: species present in the present day (all equally evolved) The great chain of being: the most basic to the very most high. Phylogenies are horizontal: sister taxa: most recent common ancestor, outgroup: most closely related group that is not in the group of interest, we want trees to show us evolutionary history. Parsimony: a preference for the least complicated explanation for a particular phenomenon, a phylogeny that requires the fewest independent evolutionary events. Occam"s razor: principle urging one to select among competing hypotheses that which make the fewest assumptions.
