Lecture 20: The History of Life on Earth

In this lecture we step back and look at the history of life on Earth from the first signs of life at start of the Archaean Eon 3.5 billion years ago to just up to the present day. We will review the appearance of photosynthesis and the rise of oxygen in the atmosphere in the Proterozoic, the appearance of the first eukaryotes and sexual reproduction, and the Cambrian explosion of plant and animal species at the start of the Phanerozoic Eon, and briefly review the changes in life to the present day from the Cambrian Explosion to the colonization of land by plants and then animals. Most of the lecture will be where most of the time was spent, in the early, microbiological Earth. Recorded live on 2009 Oct 21 in Room 1005 Smith Laboratory on the Columbus campus of The Ohio State University.