BIS 2C Lecture Notes - Lecture 1: Phylogenetic Tree, Speciation, Railways Act 1921
29 Aug 2016
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Document Summary
Phylogenies = simplifications of complex, population-level processes; also estimates of the evolutionary relationships among organisms/a set of taxa; These relationships are portrayed using a branching diagram called a phylogenetic tree. Speciation and extinction affect our inference of phylogeny; not all species may be shown and some nodes may not be resolved as bifurcating (division into two branches) lineages. Speciation from a into b and c, draw simplified branches, remove complex backbone, add node(s) Ex: many branches may not be shown because we have a taxa of interest, so some taxa may be excluded for simplicity or excluded because they are extinct. Tree of life = refers to the fact that all living organisms are related to one another through shared ancestry. Taxon =group; located at tips of the tree / taxa (plural) Taxon are connected with series of branches. Root/root branch = bottom tip of the tree; branch leading up to the root node.
