Life on Earth 1.3

A Short History of Life on Earth  The earliest life forms appeared on Earth 3.5 billion years ago  It took another 3 billion years for human history to begin  Early Homo sapiens were called Cro- Magnons  Early humans depended on their environment to survive

Homo sapiens  Species of humans  Affected their environment  Found 3 main ways to survive:  As hunters and gatherers  By farming the land  By using machines to produce what is needed

Living off the Land  The first humans lived in small groups  As seasons changed, they moved from one place to another to find food  They were called hunter-gatherers, which means they survived by hunting and collecting  Humans lived this life for most of human history

Hunter-gatherers  Knew a lot about their environment  Knew which plants could be eaten and where to catch animals  This info was passed down from one generation to the next  Small groups at first, but as their numbers grew, so did their impact on the environment  Would hunt species faster than they could reproduce

Agricultural Revolution  A period in history when hunter-gatherers learned to farm and raise animals for food  People started to stay in one place rather than move with the seasons  Farming supports 500 times more people than hunting and gathering  The number of people quickly increased

People and Agriculture  Agricultural Revolution changed people’s diets  People started eating grains (wheat, barley, rice, corn)  Farming communities thrived, people worked to build cities  New problems: waste removal, clean water

Industrial Revolution  A period in history when humans started using machines to produce food and other products  Mid-1700’s; Invention of steam engine  Allowed factories to mass-produce clothes, building materials and equipment  Made farming and transportation more efficient

Positives  Fewer people were needed to produce goods  Goods cost less being mass-produced (produced in large quantities by machine)  New inventions made people’s lives easier  Elec. Lights, cars, computers  More people could live in the same area

Negatives  Environmental problems  Large-scale farming led to a loss of habitat for many animals  Pollution from farms and factories (air, water)  Machines required more energy and resources Population Increase (pg. 15)

Vocabulary  Hunter-gatherer  Agricultural Revolution  Mass-produce  Industrial Revolution  Pollution