“…Revealing ancient hybridization in different taxa also broadens understanding of the contribution of hybridization to mammalian evolution (e.g., Marques et al, 2017). In the ground squirrels Marmotini up to a quarter of species are involved in hybridization events of varying intensity, from sporadic hybridization to the formation of hybrid zones and wide introgression according to our estimates of the literature data (Semenova, 1967;Nikol'skii et al, 1983;Smirin et al, 1985;Good et al, 2008;Stangl et al, 2012;Thompson et al, 2013;Ermakov et al, 2015;Frare et al, 2017;Ivanova et al, 2017;Leitner et al, 2017;Kapustina et al, 2018).…”