Lineage sorting by tectonic evolution: Miocene tectonism-driven diversification of the genus Saga (Orthoptera: Tettigoniidae) in the Anatolian and Balkan–Dinaric regions

In this study, the phylogenetic relationships within the genus Saga Charpentier, 1825 (Orthoptera: Tettigoniidae) have been investigated using mitochondrial (COI, Cytb, and 16S) and nuclear (ITS1–2) markers obtained from 24 populations representing nine species collected between 2012 and 2021. Phylogenetic and divergence time estimations reveal two major lineages within the genus: an Eastern Anatolia–Levant clade and a Western Anatolia–Balkan clade. The estimated crown divergence (∼19–14 Mya) dates to the early–middle Miocene and corresponds to major palaeogeographical reorganizations in the Dinarid–Balkan–Anatolian region. The East–West split coincides with the palaeogeographical barrier associated with the Bitlis Ocean/Bitlis–Zagros suture zone, suggesting that this long-standing Miocene boundary might have contributed to allopatric diversification within the genus. In addition to the land–sea shifts throughout the Miocene, the uplift of the Dinarides and Western Anatolia during this period, alongside the fragmentation of the proto-Aegean region, might have facilitated the early divergence of Saga lineages. These results provide the first comprehensive molecular framework linking diversification in Saga to Miocene–Pliocene tectonic and climatic dynamics in the Eastern Mediterranean, highlighting Anatolia as both a centre of origin and a long-term refugium for this ancient orthopteran lineage.