Human evolution favors those who can adapt to drastic changes in their environment. Archaeologists now believe that the climate can change very quickly. What would you do, if one year, spring simply didn't arrive?

The world's last ice age began between 25-30,000 years ago. For millennia, Atlantic Canada lay under a vast bed of ice. In places, the ice was four kilometers thick.

Roll over the close-up to go back in time to when the continents were conected.

Much of the world's water was frozen, trapped by the great glaciers. As the waters receded, they uncovered areas that once lay deep beneath the sea. In the north, an immense land bridge arose to link the continents of Asia and North America. Archaeologists refer to this land bridge as "Beringia." Today, we know the area as the Bering Strait.

Some archaeologists believe that hunters from Asia crossed this land bridge, into North America. These hunters would not have known they were peopling a new continent. They were simply following their prey -- the mammoth, mastodon, and bison that foraged on the open tundra. Armed only with spears, and with the help of their dogs, a small group of hunters would corner these giant mammals.

Some archaeologists believe that, as the climate warmed, the ice sheets began to separate, leading the hunters deep into the continent. An ice-free corridor, several hundred kilometers wide, may have run through today's province of Alberta.

Other archaeologists speculate that the early peoples moved down along the Pacific coast, along an exposed piece of the continental shelf. They may have accomplished at least part of this journey in skin boats. By the time rising sea levels cut off the route from Asia, the people were well adapted to their new home.

It is likely that the peopling of America from Asia involved one or more of these routes, and that the movement of population occurred very gradually, over hundreds and even thousands of years. There were no sudden and extensive migration of population. The movement of population involved a process of small groups of hunters who extended their territory gradually, generation by generation.

Eventually, both hunter and prey found themselves beyond the limits of the ice. They continued to move south, spreading to the very tip of South America. Settlement of Atlantic Canada was delayed by the ice which still covered the region. Later, as the ice melted, plants began to colonize the barren rock and animals grazed on the new growth. Once again, the hunters followed, venturing northeast from what is today the United States. Archaeologists believe that the First Peoples arrived in Atlantic Canada over 11,000 years ago.

The land they encountered was far more extensive than it is today. Freed from the weight of the ice, the land had begun to rise, while sea levels remained low. New Brunswick, Prince Edward Island, Nova Scotia, and Cape Breton were all part of a single land mass. Offshore lay immense, tundra-covered islands. Today, these islands are submerged. One lies off the coast of Newfoundland, and is known as the Grand Banks. Off Nova Scotia, another series of submerged islands forms the fishing grounds known as George's Bank. Sable Island is the lone remnant of this drowned archipelago.