Patterns of evolution and migration in the arctic ground squirrel, Spermophilus parryii (Richardson)

Abstract

Serum transferrins and 11 other genetically controlled proteins representing 17 loci were examined by starch-gel electrophoresis from Siberian, Alaskan, and Canadian populations of Spermophilus parryii. Six transferrin alleles were identified. Arctic populations (S. p. parryii, S. p. osgoodi) were characterized by Tf 6 occurring alone or together with Tf 7 whereas middle and subarctic populations exhibited Tf 7 occurring either alone (S. p. ablusus, S. p. lyratus, S. p. plesius) or together with Tf 5 (S. p. plesius). Tf 8, Tf 9, and Tf 19 constituted local variants. Tf 6 displayed a clinal distribution, increasing in frequency eastward and paralleling a clinal increase in body size. Three PGM2 alleles were observed, the frequencies of which tend to differentiate arctic S. p. parryii from subarctic S. p. ablusus. G6PD-b occurred uniformly in North America and in one Siberian population; a second population (two specimens) exhibited G6PD-a, thereby suggesting that G6PD polymorphism may be present in Siberian S. parryii. The other nine proteins were monomorphic in all Holarctic populations.

Evidence for Selective Caching by Arctic Ground Squirrels Living in Alpine Meadows in the Yukon

“…This Arcticalpine species is widespread in the Northern Hemisphere (Dormann et al, 2002), and given the large geographic range of arctic ground squirrels (Nadler and Hoffmann, 1977), it is likely that P. viviparum is an important posthibernation food for male Arctic ground squirrels in both Arctic and alpine systems. Continued research on modern and Pleistocene caches may reveal further insights into the co-evolutionary relationship between foraging behaviour and Arctic, Subarctic, and alpine habitats.…”

The effect of isolation on the morphological and genetical divergence of populations

“…This view is confirmed by the higher level of intraspecific variation of C undulatus compared to Siberian C. parryi. However, this idea is in conflict with the hypothesis of American authors (Nadler & Hoffman, 1977).…”

“…Recent discoveries of Late Pleistocene C. parryi on the north-eastern bank of the Aldan River (Vorontsov et al, 1978), (1) area, (2-7) sizes of samples: (2) 1-5 specimens; -(3) 6-10; -(4) 11-20; -(5) 21-40; -(6) 41-76; -(7) more than 100. Table 3b Genotypes and frequencies of Tf alleles in Nearctic populations of Citellus parryi Richardson (Nadler et al, 1974;Nadler & Hoffman, 1977) Subspecies, locality No. of Tfgenotypes (No observed) Tf gene frequencies speci- 5-5 5-7 6-6 6-7 7-7 7-8 8-8 9-9 9-19 dyuk, 1979), where the middle Pleistocene C. undulatus aldanensis were found, show that the scheme (Lyapunova & Vorontsov, 1970) of a united Holarctic area with a common C. undulatus-C, columbianus ancestor is in principle true (despite the fact that this area was later occupied in part by C. parryi).…”

The Beringian Coevolution Project: holistic collections of mammals and associated parasites reveal novel perspectives on evolutionary and environmental change in the North

“…In addition, the influence of smaller peripheral refugia in the Canadian Arctic (Fedorov and Stenseth 2002;Fedorov et al 2003;Cook et al 2016b), southeast Alaska Sawyer and Cook 2016), and in the periglacial zone south of the Laurentide and Cordilleran ice sheets ) is being explored. Early attempts to unravel the evolutionary history of arctic ground squirrels (Urocitellus parryii), one of the quintessential high-latitude mammals, relied on a view of Beringia as a vast steppe with few natural barriers to gene flow (e.g., Nadler and Hoffmann 1977). However, our work to test those ideas in U. parryii elucidated range-wide phylogeographic structure and a dynamic history of diversification spanning the Bering Land Bridge (Eddingsaas et al 2004;Galbreath et al 2011;McLean et al 2016b), suggesting that late Pleistocene environmental changes within central Beringia supported significant regional differentiation in this species.…”