Cosmic Impacts and Life on Earth

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 since 18 June 1999 


These are lecture notes from an experimental non-majors biology class taught in 1995 by Bruce Walsh, University of Arizona. Other lectures of potential interest:

  • Origins of life
  • Extinctions
  • Genetics class lecture notes



    The Alverez's tale

  • The Alverez Iridium anomaly
  • Iridium
  • What was the source?
  • Impact rather than Volcanic origin suggested
  • Where was the crater?
  • Crater appears to be underwater, just off the Yucatan peninsula
  • Current view
  • Earth is at risk of future impacts


    Part two of our tale: Raup and Sepkoski

  • The teaser
  • Impact theory
  • The Nemeis (Death Star) model