Origins and zoogeography of flies (Insecta: Diptera) in southern Yukon grasslands. Arctic 51

IN 1995, I took a zoogeography course at McGillUniversity with my current thesis supervisor, TerryWheeler. The purpose of zoogeographic analysis is to answer the question: “What lives where, and why? ” The question may be simple, but the answer often requires input from systematics, ecology, geology, climatology, paleoecology and other disciplines. Of all the nonbiological factors, glaciation is the single most important in deter-mining the present distribution of the Canadian biota. During the Wisconsinan glaciation, almost all of Canada was covered with ice sheets; but some areas remained ice-free, acting as refugia for many plants and animals. The best-known and best-supported refugium in the north is Beringia, which extended from eastern Siberia across the Bering and Chukchi Seas to Alaska and the Yukon. After the Wisconsinan, the Beringian flora and fauna were again connected with the rest of North America, and the newl