1 / 13

The earth’s history

The earth’s history. Review. Geologic time scale = record of earth’s history . Earth was created 4.6 Billion years ago. Its core was hot because as radioactive material decayed over time, it generated heat. . 4 billion years ago oceans formed as the planet cooled and water vapor condensed .

kalea
Download Presentation

The earth’s history

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The earth’s history Review

  2. Geologic time scale = record of earth’s history • Earth was created 4.6 Billion years ago. • Its core was hot because as radioactive material decayed over time, it generated heat.

  3. 4 billion years ago oceans formed as the planet cooled and water vapor condensed

  4. 3.3 billion years ago primitive algae formed

  5. 1.2 billion years ago multicellular organisms evolved

  6. The earth 240 million yrs ago during Pangaea (when the land was all stuck together in one mass)

  7. 200 million years ago the first mammals evolved

  8. 3 million years ago the first humanoids evolved

  9. 200,000 years ago both Neanderthals and Homo Sapiens evolved side-by-side – Neanderthals went extinct • Neanderthal vs. Homo Sapiens Scull

  10. MOST of human history we were hunter gatherers • People who obtain food from what is available in nature by collecting plants, hunting animals, or scavenging animals. • This tends towards a nomadic or ever-moving life style • Early humans could have altered their environment by over hunting a species in one region to extinction – they think this happened to the giant sloth, saber-tooth tiger, and mastodons to name a few

  11. Agricultural revolution 10,000 years ago • Led to: • Population growth – more food supports more people  waste • Buildings or primitive urbanization • Slash and burn – changes natural ecosystem • Habitat reduction  ecosystem changes  reduction in natural resources • Increase in number of domesticated animals • Farmland  Change in soil quality / loss of fertility • Flooding

  12. Industrial revolution ~ 300 years ago • A shift from energy sources and society powered by humans or animals to fossil fuels such as coal or oil. • Improvements in quality of human life • Consequences: Environmental and Social • pollution / climate change – reverse in the quality of life? • resource depletion • social inequalities? • loss of biodiversity  resource depletion

More Related