| Abstract | Island systems have long been useful models for understanding lineage diversification in a geographic context, especially pertaining to the importance of dispersal in the origin of new clades. Here we use a well-resolved phylogeny of the flowering plant genus Cyrtandra {(Gesneriaceae)} from the Pacific Islands to compare four methods of inferring ancestral geographic ranges in islands: two developed for character-state reconstruction that allow only single-island ranges and do not explicitly associate speciation with range evolution {(Fitch} parsimony {[FP;} parsimony-based] and stochastic mapping {[SM;} likelihood-based]) and two methods developed specifically for ancestral range reconstruction, in which widespread ranges (spanning islands) are integral to inferences about speciation scenarios (dispersal-vicariance analysis {[DIVA;} parsimony-based] and dispersal-extinction-cladogenesis {[DEC;} likelihood-based]). The methods yield conflicting results, which we interpret in light of their respective assumptions. {FP} exhibits the least power to unequivocally reconstruct ranges, likely due to a combination of having flat (uninformative) transition costs and not using branch length information. {SM} reconstructions generally agree with a prior hypothesis about dispersal-driven speciation across the Pacific, despite the conceptual mismatch between its character-based model and this mode of range evolution. In contrast with narrow extant ranges for species of Cyrtandra, {DIVA} reconstructs broad ancestral ranges at many nodes. {DIVA} results also conflict with geological information on island ages; we attribute these conflicts to the parsimony criterion not considering branch lengths or time, as well as vicariance being the sole means of divergence for widespread ancestors. {DEC} analyses incorporated geological information on island ages and allowed prior hypotheses about range size and dispersal rates to be evaluated in a likelihood framework and gave more nuanced inferences about... {[ABSTRACT} {FROM} {AUTHOR]}
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