Phylogeography of Pholidopterini: Revising molecular clock calibration by Mid-Aegean Trench

Abstract

The present study examines the phylogeography of Pholidopterini (Orthoptera, Tettigoniidae), a lineage distributed in the East Mediterranean and estimated substitution rates for the three mitochondrial and two nuclear gene segments. The last common ancestor of Pholidopterini was dated to 18 myr ago, in Early Miocene. Phylogeography of the lineage was marked with three waves of radiations, first during the Middle Miocene Climatic Optimum, the second during the Serravallian, and third during the ending of Messinian. The substitution rate estimations were 0.0187/0.018/0.0141/0.0010207 s/s/myr for COI/ND2/12S-tRNAval-6S/ITS1-5.8S rRNA-ITS2. The following main conclusions were drawn; (i) Radiation of Pholidopterini directed by the climatic shifts, (ii) signs of vicariant speciation were poor, contrary to the active tectonic history, (iii) the ultimate generic ancestors were dated to the Langhian and Serravallian, and (vi) the Tortonian transgression of Mid-Aegean Trench appears to be a reliable geographic calibration point for lineage splitting between Crete and Anatolia.