Lecture 20: The History of Life on Earth
In this lecture we step back and look at the history of life on Earth\nfrom the first signs of life at start of the Archaean Eon 3.5 billion\nyears ago to just up to the present day. We will review the appearance\nof photosynthesis and the rise of oxygen in the atmosphere in the\nProterozoic, the appearance of the first eukaryotes and sexual\nreproduction, and the Cambrian explosion of plant and animal species at\nthe start of the Phanerozoic Eon, and briefly review the changes in life\nto the present day from the Cambrian Explosion to the colonization of\nland by plants and then animals. Most of the lecture will be where most\nof the time was spent, in the early, microbiological Earth. Recorded\nlive on 2009 Oct 21 in Room 1005 Smith Laboratory on the Columbus campus\nof The Ohio State University.