The Traditional Scientific Theory of the Origin of the First Americans “The Clovis Model” The Evolution of Humans The Bering Land Bridge The Ice-Free Corridor The Clovis Barrier Spreading through the Americas
The Evolution of Humans• The theory of evolution is widely accepted by scientists, but many religions do not accept the idea.• Scientists believe humans evolved. Some early monkeys led to apes. One group of apes evolved into humans• Human evolution occurred in Africa• Humans were hunters and gatherers - developing uniquely human characteristics - – walking on two feet – tools – language – fire – shelter and clothing
The Evolution of Humans - 2• Four types of humans evolved – Negroid in Africa – Caucasoid in Europe and western Asia – Australoid in Australia – Mongoloid in eastern parts of Asia• By about 50,000 years BP they were able to move out of tropics into coldest areas of the earth - reached all through the Old World as far as Australia and Siberia• At this time scientists believe there were still no humans in the Americas
The Bering Land Bridge• Scientists believe humans moved from Siberia into Alaska and the Yukon perhaps as long ago as 40,000- 25,000 years BP• They were able to cross on foot where the Bering Strait is today – Sea levels went down as a result of the last ice age – During the ice age the normal water cycle did not work – Precipitation was frozen and trapped in huge glaciers or ice sheets – The ice sheets were as thick as 3000 metres – Sea levels went down as huge amounts of water were trapped in the ice sheets – the Bering Strait was above sea level - the land there has been called the Bering Land Bridge or Beringia – Beringia may have been 600 km wide from north to south
The Ice Free Corridor• Scientists believe humans reached Alaska and the Yukon by at least 25,000 years BP by way of the Bering land Bridge• These first Americans were big game hunters• Scientists believe the ice sheets did not cover Alaska and the Yukon, but covered almost all of the rest of North America south of the Yukon• About 14,000 years ago the temperature of the earth began to warm• 11,000 - 10,500 years BP the ice sheet on the Rocky Mountains separated from the ice sheet over central Canada, and a corridor along the eastern side of the Rockies opened• Humans moved through the corridor into the southwestern parts of the United States• Humans then spread rapidly through the unglaciated parts of the Americas
The Corridor Opens18,000 years ago | 14,000 years ago
4. The Clovis Barrier• Archaeologists found a spear point at Clovis in New Mexico• It was the oldest clearly datable artifact made by humans - it dated to 10,500- 11,000 BP• It was found in with bones of a mammoth, which became extinct 10,000 years ago• Clovis points were found widely through North America• No earlier traces of human activity could be clearly proven before the Clovis dates• Evidence of human activity soon after this date is found all the way to the southern tip of South America• Evidence of human big game hunting traditions is widespread after the Clovis dates• Scientists believed (in the 1970s) that no humans entered the Americas before the Clovis dates• Evidence for any earlier human presence could not be found - the Clovis dates were a barrier. Before this there was no clear evidence.
5. Spreading through the Americas• The original big game hunters who entered the Americas south of the Yukon moved rapidly through the new environment• Many animals became extinct in the Americas soon after this – mammoths – mastodons – horses – camels (in North America) – giant bison• Human hunting may have been a factor, together with changes in environment• Big game hunters moved into new environments, and adapted, finding new ways to live• Many new cultures arose in the new environments