Conflict between nuclear and mitochondrial DNA phylogenies of a recent species radiation: What mtDNA reveals and conceals about modes of speciation in Hawaiian crickets

<jats:p> It has been asserted that recent mtDNA phylogenies support the plausibility of sympatric speciation, long considered a controversial mechanism of the origin of species. If such inferences are reliable, mtDNA phylogenies should be congruent with phylogenies based on other data. In previous work, a mtDNA phylogeny suggested that diversification of the Hawaiian cricket genus <jats:italic>Laupala</jats:italic> was initiated by single invasions into each of several Hawaiian islands, followed by multiple sympatric divergences within each island. In contrast, a systematic hypothesis based on morphology argues that speciation in <jats:italic>Laupala</jats:italic> has occurred primarily in allopatry, with two independent species radiations diversifying across the archipelago. In this study, I analyze nuclear DNA (nDNA) sequences from <jats:italic>Laupala</jats:italic> to compare with sequences from the mtDNA. The nDNA phylogeny corroborates the hypothesis of allopatric divergence and multiple invasions, and when compared with mtDNA patterns, suggests that interspecific hybridization is a persistent feature of the history of <jats:italic>Laupala</jats:italic> . The discrepancy between mtDNA and nDNA phylogenies reveals that speciation histories based on mtDNA alone can be extensively misleading. </jats:p>