BIOL359 Midterm: bio359review after midterm.docx

• School: University of Waterloo
• Department: Biology
• Course: BIOL359
• Professor: Jonathan Witt

Document Summary

Phylogenetics : the study of ancestor desendent relationships. All life forms are related by common ancestry and descent. We use characters to construct phylogenies. A character is any attribute of an organism that can provide us with insights into history (shared ancestry) In molecular phylogenies, characters are typically nucleotide positions in a gene sequence, and each position can possess four character states: a,c,g,or t. Synapomorphy: a derived character state(apomorphy) that is shared by two or more taxa due to inheritance from a common ancestor: these character states are phylogenetically informative using the parsimony or cladistics criterion. The tree with the least number of steps is the most parsimonious. Computational technique for estimating the confidence level of a phylogenetic hypothesis. Paraphyletic contain some but not all descendants of a common ancestor, or polyphyletic( erroneous homoplasious groupings) The comparative method in evolutionary biology evaluates the strength of hypotheses by testing for patterns across species or lineages.