Evolutionary history of the Persian squirrel (Sciurus anomalus): It emerged on the Eurasian continent in the Miocene

The Persian squirrel (Sciurus anomalus) is limited to the Irano-Anatolian region of western Asia. The evolutionary history and phylogenetic status of the Persian squirrel are ambiguous. Here, we present a molecular phylogeny using mitochondrial and nuclear genes (D-loop noncoding region, Cyt b, COI, Cmyc, and Rag1) for S. anomalus and other Sciurus species. Our analyses revealed three major clades comprising (i) Sciurus species in North America, (ii) Sciurus vulgaris and Sciurus lis in Eurasia and (iii) S. anomalus in western Asia. For mitochondrial and nuclear genes, uncorrected genetic distances between S. anomalus and each of the two other clades were similar. We conclude that the divergence of S. anomalus from the ancestor of New World species occurred on the Eurasian continent during the Miocene period 10 Mya (HPD: 11-8 Mya), with the ancestral New World species then moving from Eurasia through Beringia to North America. During the Pleistocene period S. anomalus gradually became widespread in association with prevalent woodlands throughout the Irano-Anatolian terrain and the eastern coast of the Mediterranean Sea. Today we find this species in fragmented forests in and around the Mediterranean Sea, Anatolia (Turkey) and in the Zagros Mountains (western Iran). (c) 2020 Elsevier GmbH. All rights reserved.