BIOL 1000 Lecture Notes - Lecture 26: Population Ecology, Pair Bond, Polytomy
8 Sep 2016
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Document Summary
Working with phylogenetic trees: the unity and diversity of life . Reading a phylogenetic tree: branches represent populations through time. And indeed they are usually drawn with less than a full set; often a representative taxon" is used. (taxon is a general term for any name, where a species or genus, family, etc. ) There are two general strategies for using data to estimate trees: the phenetic and the cladistics approaches. The phenetic approach: is based on computing a summary based on overall similarities of the taxa" considered. A computer program builds a tree that clusters the most similar taxa and places more divergent taxa on longer branches. The cladistics approach to inferring trees focuses on synpomorphies, the shared derived characters of the species under study. When many such traits have been measured, traits unique to each monophyletic group are identified and the groups are placed on a tree in the appropriate relationship to one another.
