HY 101 Chapter 1: HY Notes 1
Document Summary
225 million years ago - pangaea started to break apart. 10 million years ago - north america was shaped by nature - canadian shield. 35,000 years ago - the oceans were glaciers and the sea level dropped, leaving an isthmus connecting asia and north america. The bering isthmus was crossed by people going into north america. 10,000 years ago - ice started to retreat and melt, raising the sea levels and covering up the bering isthmus. Evidence suggests that early people may have come to the americas in crude boats, or across the bering isthmus. By the time columbus arrived in america in 1492, over 54 million people may have been living in north & south america. Unlike in mexico with the aztecs, dense populations did not exist in north america. This may have made it easier for the europeans to colonize the continent. People of europe were able to reach sub-saharan africa around 1450 when the.
