Biology 1001A Chapter Notes - Chapter 20: Stapes, Cladistics, Phylogenetic Nomenclature
Document Summary
Darwin"s conception of branching evolution a tree of life: evolutionary tree shows domains of life. Phylogeny: the evolutionary history of a group of organisms: presented as phylogenetic trees: a branching diagram depicting the evolutionary relationships of groups of organisms. Formal hypotheses identifying likely relationships among groups of organisms. Accurate phylogenetic trees essential components of comparative method biologists use to analyze evolutionary processes: good phylogenetic hypotheses allow distinguishing similarities inherited from common ancestor from those that evolved independently in response to similar environments. Try to exclude differences caused by environmental condition. Do not use number of pads on fourth toe of right hind foot as separate character because same genes almost certainly control number of pads on the toes of both hind feet. Limbs of tetrapod vertebrates are homologous characters similar in evolutionary history but not necessarily function. Homologous characters useful in preparing phylogenies because they reflect underlying genetic similarities. Comparison of homologous characters can indicate ancestry/genetic relatedness.
