Mitogenomic Insights into the Evolution, Divergence Time, and Ancestral Ranges of Quails.

The Old-World quails, (common quail) and (Japanese quail), are morphologically similar yet occupy distinct geographic ranges. This study aimed to elucidate their evolutionary trajectory and ancestral distribution patterns through a thorough analysis of their mitochondrial genomes. Mitogenomic analysis revealed high structural conservation, identical translational mechanisms, and similar evolutionary pressures in both species. Selection analysis revealed significant evidence of positive selection across the lineage for the gene tree owing to environmental changes and acclimatization requirements during its evolutionary history. Divergence time estimations imply that diversification among species occurred in the mid-Miocene (13.89 Ma), and their current distributions were primarily shaped by dispersal rather than global vicariance events. Phylogenetic analysis indicates a close relationship between and , with divergence estimated at 2.25 Ma during the Pleistocene epoch. Ancestral range reconstructions indicate that the ancestors of the clade were distributed over the Oriental region. subsequently dispersed to Eurasia and Africa, and to eastern Asia. We hypothesize that the current geographic distributions of and result from their unique dispersal strategies, developed to evade interspecific territoriality and influenced by the Tibetan Plateau's geographic constraints. This study advances our understanding of the biogeographic and evolutionary processes leading to the diversification of and , laying important groundwork for further research on this genus.