BIOL108 Study Guide - Final Guide: Allopatric Speciation, Nitrogen Fixation, Sympatric Speciation

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

Phylogenetic trees: each level is a taxon, pl. taxa. A clade is a grouping of an ancestor and its descendants. Relationships determined by order of branching, not arrangement of taxa. Systematists collect info about morphology, behavior, dna, biochemistry. Related but split off early enough to be different enough to compare/contrast. Use occams razor when designing phylogenetic trees (principal of parsimony) Enter information into matrix, code states as 0 for ancestral (outgroup) and as 1 for non-ancestral or derived. Termed character-state polarization because direction of changes is decided. From here determine set of nested relationships w/ fewest possible changes. Determination of a clade is supported by synapomorphy shared, derived state. Clades are relative and depend on the starting point/trait chosen to examine. Homologous v analogous characters = homologous evolution v convergent evolution. Monophyletic group: contains a common ancestor and all of its descendants and no other taxa (=clade).