Evolutionary Biology BIOL 3350 Dr Lisa Rapaport Lecture 14 Part 1 Notes I II IV Reconstructing Evolutionary Histories Taxonomy A Linneaus developed the system of binomial nomenclature that we still use today Phylogenetic trees A Phylogenetic trees are hypotheses B Don t know for sure that they are the real truth because evolution is a very long process and hard to observe entirely C Phenotypes are a result of the interaction with the environment so they do not necessarily mean common ancestry D Grouping taxa together with the smallest distance between them E Homoplasy similarity of use similarity of function but not similarity of ancestral history F Most recent common ancestor had the new a trait G Ex scattered spots you see on a bobcat rosette pattern on modern jaguars III Distinguished from homoplasies A Mutations do not always occur in one direction B The more characters you use the more certain you can be that your hypothesis is correct C Evolutionary reversals are not that uncommon D Homology the stripped pattern is a result of shared ancestry E Evolutionary reversal mutations can go in both directions forward F and backwards In order to make phylogenetic trees we are looking for homology common ancestry Using DNA A DNA is a really good measure to use when comparing the similarities between organisms B Red indicates that the nucleotides are the same and black indicates that the nucleotides are different C Keeping alignment of amino acids with insertions and deletions in mind is important D You need a large number of traits in order to have a firm hypothesis E Synapomorphy trait shared by the last common ancestor but not F The length of the branches between 2 groups relates to the time since by the ancestor before that the last common ancestor 1
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