Early HumansPart I: Migration

•Humans have spent nearly 75% of their time on Earth in Africa

•Earliest human records are from 200,000 years ago

•Earliest evidence of leaving Africa is between 70,000 and 60,000 years ago

Why the move?•Probably climate change

•A rapid cooling of the Earth made life difficult for humans in Africa

• In fact, the human species almost became extinct!

• It is estimated that the human population dipped below 10,000 adults at this time, which is to say we were hanging on by a thread!

•Between 70,000 and 60,000 years ago, high levels of sea ice narrowed the gap between the Horn of Africa and the Middle East

•A few explorers likely made the 12 mile-or-so trip in a raft of some kind

•From the Middle East, our ancestors spread east through Arabia and Asia

•Within a few thousand years of reaching Asia, their seafaring technology had advanced enough to allow them to island hop to Australia

•Europe was much colder during the cool period

•As such, early humans didn’t arrive in Europe until around 40,000 years ago

•They took a route through the Middle East, then up through Central Asia before finally swinging west into Europe

•Finally, around 20,000 years ago, our ancestors left Eastern Asia via a land bridge to North America

•Within 1,000 years, they had made it to the southern half of South America