1. Life on Earth 1.3

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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)

11. Vocabulary • Hunter-gatherer • Agricultural Revolution • Mass-produce • Industrial Revolution • Pollution