Testing biogeographic hypotheses with cladistic analysis

Testing biogeographic hypotheses with cladistic analysis -...

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Testing biogeographic hypotheses with cladistic analysis. Brundin's midges (fig. 18.7, 18.8, pg. 519-520) a classic in vicariance biogeography. Sibley and Ahlquist's Ratites and the Gondwana breakup. Testing hypotheses about the sequence of vicariance events with cladograms from several species. Validity of biogeographic hypothesis can be supported by congruence of independent cladograms from unrelated species (see Cracraft, 1983, American Scientist vol. 71: pg273). By considering the relationships of organisms and their geographic distributions, the most parsimonious combination of the species cladograms can lead to an hypothesis of vicariance events, a so- called area cladogram which presents the sequence of splitting events.
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Unformatted text preview: Using cladistic methods, one can test biogeographic hypotheses by asking whether area cladograms for other, unrelated taxa are congruent . If different taxa all have similar area cladograms (i.e., are "congruent"), then the sequence of vicariance events is supported. If one taxon is represented in a region where none of the other taxa are found, then one might be forced to invoke dispersal to account for the disjunct distribution. The strength of this approach is that hypotheses are testable and one need not resort to ad hoc explanations that should be taken on faith. Biogeography can be practiced in a scientific manner despite itshistorical nature....
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This note was uploaded on 11/06/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

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