The flightless beetle genus Tarphius Erichson (Coleoptera: Colydiidae) is a distinctive element of the betle fauna of the Canary Islands with 29 species distributed across the five western islands. The majority of Tarphius species are rare and inimately associated with the monteverde forest and only two species occurr on more than one island. It this study we investigate the phylogeography of the Canary Island Tarphius, and their relationship to Tarphius from the more northerly archipelagos of Madera and the Azores using Maximum parsimony and bayesian inference analysis of mitochondrial cytochrome oxidase I and II sequence data. We use geological datings for the Canary Islands, Azores, and Madeira to calibrate specific nodes of the tree for the estimation of divergence times using a penalized likelihood method. Data suggest that the Canary Island species assumblage is of some antiquity, however, much of this species diversity is relatively recent is origin. The phylogencetic relationships of species inhabiting the younger islands of EI hierro and LaPalma indicate that coloniztion events between islands have probably been a significant factor in the evolutionary history of the Canary Island species assemblage. A comparison of molecular phylogenetic studies of arthropods on the Canary Island suggests that, in the evolution of the arthropod species species community of an island, the origin of endemic species is initially the result of colonizing lineages differentiating from their source populations. However, as an island matures a greater proportion of endemic species originate from intra-island speciation.
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|Published - 2005