From: The Encyclopedia of Canada's Peoples/Peopling/R. Cole Harris
The human occupation of the Western hemisphere probably began when Asian big-game hunters crossed the Bering land bridge into Alaska more than 15,000 years ago. As the ice sheets melted, these people spread southward, peopling North and South America. Their large fluted projectile points (for spears) are found from Alaska to Chile; DNA analysis confirms the common ancestry, traceable apparently to this migration, of most of the native peoples of the Western hemisphere. A second Asian migration began at least 11,000 years ago. These Northern Interior Microblade people, named after their small, thin, razor-sharp flakes (fitted around the edge of a projectile point or knife), spread into Yukon and northern British Columbia and, later, east almost to Hudson Bay and were the ancestors of the Athapascanspeaking peoples of northwestern Canada. Much later, about 4,000 years ago, Paleo-Eskimo people spread eastward across the high Arctic, occupying the last major unsettled but habitable region on earth. Out of their migration evolved Dorset culture, which was displaced about a thousand years ago by the Thule, a powerful, eastward-advancing people equipped with boats, float harpoons, sinew-backed bows, dog-sleds, and stone and whalebone houses.
With these migrations all of Canada was occupied. In the process, people settled down and cultures adapted to different environments. Such adaptations, together with the diffusion of ideas, had far more to do with cultural change than the migration of people. Many of the main innovations, such as the bow and arrow and pottery (introduced from the south and the far northwest about 3,000 years ago) or agriculture (introduced to southern Ontario from the south about 1,500 years ago), were added to well-established cultures. Characteristically, the people of these cultures had lived in much the same places, coping with much the same environments, for longer than the collective memory, preserved in stories, could remember – since “time immemorial” their descendants would say in court cases over land claims.
About 10,000 years ago on the plains, changes in stone-tool technology introduced what archaeologists call Plano culture, which, with the introduction of notched projectile points 2,000 years later, became an archaeologically identified succession of early plains cultures. Behind this taxonomic variation was a great deal of cultural continuity among bison hunters descended from Fluted Point ancestors. In the Cordillera, Fluted Point people, or their close descendants, entered southern British Columbia from the south, while Northern Interior Microblade people settled the coast to the north. Increasingly productive salmon, halibut, eula– chon, and shellfish fisheries and the growing availability of red cedar underlay the emergence, at least 4,000 years ago, of many elements of the historic northwest coast cultures.
Around much of the Canadian Shield, Plano culture developed into what archaeologists call Shield Archaic, which, judging by the location of archaeological sites, identifies people living in small bands and dependent primarily on caribou and fish. In those instances where Shield Archaic encompasses pottery, it has been relabelled Laurel by archaeologists. Among the small bands of hunting-fishing people in the seasonally semiaquatic environment of the Canadian Shield, there was a common line of descent from Fluted Point, to Plano, to Shield Archaic, to Laurel in some areas, to the historic Algonquian (Cree, Ojibwa Algonquin, Montagnais). In southern Ontario and the St Lawrence valley, Fluted Point and Plano beginnings evolved into Laurentian Archaic, a culture dependent on deer, fish, small game, a variety of edible plants, and a tool kit that borrowed heavily from peoples around the Gulf of St Lawrence.
Archaeologists have identified several cultures that descended from Laurentian Archaic; these cultures, which emerged after the introduction of pottery 3,000 years ago, were in turn the ancestors of the historic Iroquoian peoples. Maritime Archaic cultures, which dominated Atlantic Canada for some 6,000 years, disappeared about 2,500 years ago, its relationship with proto-Micmac, Malicite, and Beothuk cultures poorly understood. But this taxonomic cultural change, associated principally with evolving stone-tool technologies, tends to mask two basic underlying realities: few migrations after initial peoplings and long cultural continuities.
In 1500 C.E. the population of what is now Canada comprised many regional cultures, each dependent on meticulous knowledge of local environments and on trade and alliances with neighbouring peoples. Intricate accommodations of people, environment, and technology had been worked out in situ over countless generations. Agriculture was practised only in southern Ontario and the St Lawrence lowland; elsewhere people hunted, fished, and gathered in various combinations; in different environments their lives revolved around quite different annual cycles of food procurement. Everyone assumed that lives, all phenomena, were enveloped by spirit power and sought to live as harmoniously as possible within a spirit world. Everywhere social control was local; even in the most elaborated social hierarchies, no one had much coercive authority over many others. Localness was reflected in a great variety of dialects and languages, although three linguistic families, Algonquian, Athapascan, and Inuktituk, each associated with a different early migration, dominated most of the area of Canada.
Until recently it was assumed that about 250,000 people lived in Canada c. 1500 C.E. However, this figure was calculated within a hemispheric estimate of 6–8 million, now known to be much too low. Although a reliable estimate of the population of Canada 500 years ago cannot be made, it is clear that in most of Canada the biotic carrying capacity (the extent to which an environment can support plants and animals) was low, and that the human population density was also low. More food was available where agriculture was practised, or where bison or salmon and other marine resources were available. By far the highest population densities, apart from the Iroquoian agricultural settlements in southern Ontario, were along the northwest coast and up the salmon rivers nearby. Current estimates of the contact population in British Columbia are as high as or higher than estimates made a few years ago for all of Canada.