Evolution of Poecilimon jonicus group (Orthoptera: Tettigoniidae): a history linked to the Aegean Neogene paleogeography

Abstract

The Aegean archipelago is among the largest on Earth with astonishing biodiversity within Europe. Its territory underwent a massive geotectonic transformation in Neogene that resulted in multitude of changes in land-sea configuration and disintegrated the formerly united Aegean land to a complicated mainland-archipelago system. Therefore, it represents an excellent laboratory for studying evolution of terrestrial fauna. In the present study, we use a model group of flightless bush crickets with annual reproduction cycle—Poecilimon jonicus species group—to trace correlation of lineage diversification with the known paleogeographic events in the Aegean area. The group belongs to the hyperdiverse genus Poecilimon and has a disjunct distribution along the Hellenic arc from southwestern Anatolia through Crete to the western Balkans and the Apennines. To test our hypothesis, we inferred phylogenetic relationships of the P. jonicus group sensu lato using a nuclear fragment covering two spacers of the ribosomal cistron (ITS1 + ITS2). To study intra-group phylogeny, we compared mitochondrial phylogenies based on two matrices—(1) a concatenated ND2 and COI dataset of 1656 bp and (2) a 16S rRNA + 12S rRNA dataset of 1835 bp. As a second step, we estimated divergence times applying Bayesian approach with BEAST and a relative rate framework with RelTime on the mitochondrial matrices. We compare trees calibrated based on evolutionary rates and tectonic events and discuss radiation scenarios in concordance with known paleogeographic events in the Aegean area. Our results revealed robust phylogeny of the Poecilimon jonicus group and confirmed a strong link between its evolution and the Aegean paleogeography. The phylogenetic relationships of the group supported reconsideration of its systematics.

Phylogeography of the Poecilimon ampliatus species group (Orthoptera: Tettigoniidae) in the context of the Pleistocene glacial cycles and the origin of the only thelytokous parthenogenetic phaneropterine bush-cricket

“…Choosing calibrations for molecular dating could be challenging, especially when fossil data is unavailable. A recent study estimated divergence dates in Poecilimon, using the isolation of Crete as a source of age constraint (Borissov et al 2020). The split of the easternmost lineage of the only Cretan species P. cretensis Werner, 1903 was estimated at 0.8 Ma, possibly reflecting its allopatric evolution due to former disconnection of the easternmost part of Crete.…”

“…Heller et al 2006Heller et al , 2011Chobanov and Heller 2010;Kaya et al 2012;Boztepe et al 2013;Kaya et al 2018). Molecular phylogeny supported monophyly of many species groups (Ullrich et al 2010;Boztepe et al 2013;Kaya 2018;Borissov et al 2020), yet some systematic problems remain unsolved (Ullrich et al 2010;Chobanov et al 2020). Diversity of Poecilimon is concentrated in the southern Balkans, Anatolia and the Caucasus with very few taxa spreading outside this range.…”

Origin, evolution and systematics of the genus Poecilimon (Orthoptera: Tettigoniidae)—An outburst of diversification in the Aegean area

“…A total of 64 sequences of ND2, COI and ITS1 + 5.8 S + ITS2 were obtained in the present study. In addition to the newly obtained data, DNA sequences of the latter fragments were available from own previously published works (Borissov et al, 2020, 2021; Borissov & Chobanov, 2020; Chobanov et al, 2017), while additional sequences for the corresponding taxa from the nuclear 28 S rRNA gene and a mitochondrial fragment of 12 S rRNA+tRNA‐Val + 16 S RNA (e.g., Ullrich et al, 2010) were downloaded from GenBank. In order to cover more taxa, the entire nuclear dataset (ITS1 + 5.8 S + ITS2) from Ullrich et al (2010) was accessed from GenBank, compiled with other published and new data, and processed separately as described below.…”

“…The Aegean Basin and its neighbouring areas have long attracted the scientists' attention for studying phylogeographic patterns in terrestrial animals (for a review see Poulakakis et al, 2015; also Avtzis et al, 2021; Borissov et al, 2020; Chobanov et al, 2017; Çıplak et al, 2022; Kaya & Çıplak, 2017; Kornilios et al, 2019; Trichas et al, 2020) as a result not only of the area's tempestuous geological history related to the Tethian tectonic belt (Robertson & Mountrakis, 2006) but also for its vast biological diversity.…”

“…The genus Poecilimon was more or less thoroughly treated in several publications concerning its systematics (Borissov et al, 2020, 2021; Boztepe et al, 2013; Chobanov et al, 2020; Chobanov & Heller, 2010; Heller, 1984; Heller et al, 2006, 2008, 2011; Heller & Sevgili, 2005; Kaya, 2018; Kaya et al, 2012, 2015, 2018; Ramme, 1933; Sevgili et al, 2018; Ünal, 2010) and phylogeny (Borissov et al, 2020, 2021; Kaya et al, 2015; Ullrich et al, 2010). Yet, due to the high number of taxa, groups containing sibling species of recent origin (e.g., compare Borissov et al, 2021; Kaya et al, 2015), complex diversification patterns (Borissov et al, 2020; Heller, 2006) and different methodologies applied (e.g., compare Borissov et al, 2020; Kaya et al, 2018; Ünal, 2010), systematic arrangements and number of taxa are still disputable. Even more intriguing are the main evolutionary forces driving the Poecilimon intensive diversification within restricted spatial and temporal scale, among which ecological (habitat/climate driven diversification) and non‐ecological (song specialization driven by sexual selection and/or genetic drift) radiations may have largely contributed.…”