Assessing Genetic Diversity and Habitat Suitability in Endemic Iranian Darevskia (Reptilia: Lacertidae) Under Climate Change

Abstract

The Iranian Plateau, a biogeographic hotspot shaped by Pleistocene refugia and topographic complexity, hosts six endemic Darevskia lizard species (D. caspica, D. defilippii, D. schaekeli, D. kamii, D. steineri, and D. kopetdaghica), ideal for studying evolutionary responses to environmental changes. These species, characterized by cryptic diversity and narrow ecological niches, face threats from habitat loss and climate change. We integrated population genetics and ecological niche modeling (ENM) to assess their genetic diversity, population structure, and future habitat suitability. Using cytochrome b and MC1R gene sequences (1248 bp, 75 sequences), we found high haplotype diversity (e.g., D. schaekeli, Hd = 0.985) and evidence of historical population expansion (raggedness = 0.0052, τ = 34.204), suggesting refugial persistence in the Hyrcanian forests and Alborz Mountains. Darevskia steineri showed low diversity and high gene flow indicating demographic stability. Phylogenetic analyses confirmed species distinctiveness but revealed intra-lineage structuring in the Persiodarevskia group. Maxent-based ENM, using WorldClim data, project significant habitat contractions and elevational shifts by 2070 across four climate scenarios, with D. kopetdaghica and D. kamii most vulnerable due to restricted ranges. Temperature extremes and precipitation seasonality emerged as key climate drivers. By combining genetic distinctiveness with ENM, we identify conservation priorities, emphasizing microrefugia preservation and range-edge monitoring. These findings underscores the role of historical biogeographic processes in shaping Darevskia diversity and highlight their vulnerability to climate-driven habitat loss, urging target conservation to safeguard their evolutionary legacy.