A review of molecular data for the phylogeny of basal hexapods

Moleculardata have been increasingly used to study the phylogenetic relationships among many animal taxa, including arthropods. Sometimes they have provided phylogenetic reconstructions that are in conflict with morphological data leading to a re-evaluation of long-standing evolutionary hypotheses. In this paper, we review the major contributions to the phylogeny of hexapods based on moleculardata, with emphasis on the relationships of basalhexapod taxa. The placement and the monophyly of the five basalhexapod lineages (the “apterygotes”: Protura, Collembola, Diplura, Microcoryphia and Zygentoma) are one of the hottest issues in arthropod phylogeny. We discuss methods of data collection and analysis, and we describe the areas of conflict and agreement between molecularphylogenies and the evidence provided by morphological characters.