Factors of Extinction

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Factors of Extinction
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Extinction

• A species is extinct if no members of that
  species are still alive.
• Most organisms that have ever lived on Earth are
  now extinct.

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Natural Factors

• Volcanoes spewing greenhouse gases causes global
  warming
• global cooling during ice ages often caused by
  volcanic debris in atmosphere
• changes in oxygen levels in seawater
• a massive impact from an asteroid or comet
• Plate tectonics can affect global climate patterns

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Natural Factors

• Natural extinctions have occurred throughout
  geologic history.
• Not all have been negative, in that extinctions
  often clear the way for new kinds of life.

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Human Factors

• deforestation
• removing natural habitats
• over-harvesting
• pollution
• Man-made factors have caused extinctions in more
  recent times.