Transcontinental evolutionary dynamics and phylogeography of Alectoris (Aves: Galliformes): Identifying refugia, dispersal corridors, and cryptic diversity in the Palearctic region

Abstract

The Alectoris (Galliformes: Phasianidae) has a wide distribution range in the Palearctic region, with seven species and 27–31 subspecies that were distinguishable by minor morphological differences. The members of the genus exhibit distinct genetic structuring compatible with geography due to their inability to make long flights and ground-dwelling behaviors. In this respect, the evolutionary history of the genus and its populations is a useful tool for identifying potential cryptic refugia, dispersal corridors, and strong barriers for bird species in the Palearctic region. On the other hand, wild populations of the genus are among the bird species most affected by human activities. For this purpose, sequences from the mitochondrial D-loop and Cyt-b regions of individuals from the genus Alectoris were studied to identify the evolutionary history of the genus, determine potential cryptic species, and reveal possible hidden diversification areas in the Palearctic region. The results indicated that: the Mediterranean basin is the ancestral area of the Alectoris, there are two main diversification centers within its distribution range (Mediterranean Basin and China) of the genus, and certain micro-refugia and permanent dispersal corridors have been observed in Eastern Palaearctic region. Additionally, the results showed that the Pleistocene climatic changes acted as a species pump, playing a significant role in the diversification of lineages within the genus. Anatolia served as the ancestral area for the A. chukar and acted as a bridgehead during the species' dispersal in the inner side of the Eastern Palaearctic. High mountain ranges, monsoonal climate types, and deserts in the Eastern Palearctic played a significant role in the dispersal and diversification of the ancestral A. chukar population. Importantly, human activities appear to be the greatest evolutionary force shaping the future evolution of the genus.