Glacial refugia, haplotype distributions, and clonal richness of the Daphnia pulex complex in arctic Canada

摘要: As part of a large international Arctic biodiversity expedition (Tundra Northwest '99), we examined the distribution members arctic Daphnia pulex complex (Cladocera, Anomopoda) from 121 tundra ponds, spread across 16 sites spanning portion Canada (i.e. 62 degrees 22' N to 79 01' N; 66 45' W 139 37' W). Using allozyme electrophoresis and mitochondrial (mt)DNA analyses, population genetic (clonal) structure these populations. The following taxa were detected in this complex: pulicaria, D. middendorffiana tenebrosa. Clear geographical differences mean clonal richness diversity observed, with most western exhibiting higher diversity, than eastern Canadian Arctic. For both pulicaria group middendorffiana) tenebrosa, highest regional was southern section Banks Island, an unglaciated site situated on edge or directly fringe Beringian glacial refuge. A significant negative correlation found between distance edge, overall closer harboured greater richness). These results clearly indicate that more recently deglaciated regions Arctic) harbour lower levels nearer Beringia. We discuss role refugia have played influencing biotic taxa.