Genetic Diversity in Arctic Lemmings

摘要

The Tundra Ecology –94 expedition offeredunique opportunities to study genetic diversity inlemmings along 6000 km of the Arctic coast of Eurasia.Comparisons were made within and among populations,among geographic regions, and between species. One aimof our study was to contribute with molecular data tosolve taxonomic problems present in true lemmings(Lemmus). MtDNA studies made it possible to clarify thephylogenetic relationships among various populations,and thus it was logical to divide the present speciesL. Sibiricus into two, L. Sibiricus and L bungei. Anotheraim was to describe the chromosome races in collaredlemmings (Dicrostonyx) and explain their origin. Fourchromosome races and their distribution along the coastwere established in D. torquatus. The races are mainlycharacterized by a sequence of translocations betweensex chromosomes and autosomes. Our studies confirmedthat the collared lemmings on Wrangel Island belong toanother species, D. groenlandicus, and it was proventhat the colonization history of Wrangel Island wascompletely different for Lemmus and Dicrostonyx.