• more than 99% of all organisms that have ever lived on the earth are now extinct
  • new species evolve and the old die away to fit changing ecological niches
  • but the rate of extinction is not constant
  • 5 times in the last 500 million years 70/90% of all species on earth have disappeared in mass extinctions
  • they open up the planet for new forms of life to emerge
  • one mass extinction was the boundary between the Cretaceous->Paleogene    periods (killed off the Donavan dinosaurs and made room for man)
Mass Extinctions (unfinished) / Rose Hinton by blogadmin is licensed under a Creative Commons Attribution CC BY 3.0