Genomic inferences in a thermophilous grasshopper provide insights into the biogeographic connections between northern African and southern European arid‐dwelling faunas

Aim Although thermophilous and arid‐dwelling relict biotas constitute a singular component of European biodiversity of high conservation value, we still largely ignore their biogeographic history. In this study, we investigate the geographical diversification of the Maghrebian‐Levantine crested grasshopper and its colonization of semiarid habitats of southeastern Iberia to gain insights into the historical processes underlying the biogeographic connections between northern African and southern European arid‐dwelling faunas. Location Mediterranean region. Taxon Crested grasshoppers Dericorys millierei and Dericorys carthagonovae (Orthoptera: Dericorythidae). Methods We used genomic data (ddRAD‐seq) to quantify the genetic structure of populations, infer the phylogenetic relationships among them, estimate divergence times, and elucidate the demographic processes accompanying the colonization of southeastern Iberia. Genomic‐based inferences were interpreted in the light of eustatic sea‐level reconstructions and species’ range dynamics derived from palaeodistribution modelling at fine temporal resolution. Results Clustering analyses showed a strong genetic structure and phylogenomic inference revealed that Iberian populations are nested within a Maghrebian clade. Molecular dating analyses indicated that all lineages diverged during the Pleistocene (