Analysis of vicariant distributions: A method and software for using direct geographic information in historical biogeography

ARIAS J.S.; C. SZUMIK; P. GOLOBOFF.

Honolulu, Hawaii

Congreso; XXIX Willi Hennig Meeting; 2010

University of Hawaii - American Museum of Natural History

Based on Hovenkamps ideas on historical biogeography, we present a method for analysis of taxon history, spatial analysis of vicariance, which uses observed distributions as data, thus requiring neither predefined areas nor assumptions of hierarchical relations between areas. The method is based on identifying sister nodes with disjunct (allopatric/vicariant) distributions. To do this across the tree, internal nodes are assigned distributions (as the sum of the distributions of the descendant nodes). When distributions are less than ideal, ignoring the distribution of the problematic node(s) when assigning a distribution to their ancestors may allow us to consider additional sister nodes (i.e. those resulting from splits basal to the problematic node) as having disjunct distributions. Theoptimalitycriterion seekstofindthebest(possiblyweighted)compromisebetweenthe maximumpossible number of disjunct sister nodes and the minimum number of eliminated distributions. The method can also take overlap into account. The methodology presented is implemented in VIP, a computer program available at http://www.zmuc.dk/public/phylogeny/vip.