Lecture 18: The First Living Things on Earth

What are the first recognizable forms of life that we find in the geological record? How far back can we go in geological time and still find life? This lecture reviews three lines of evidence that have emerged in recent years to suggest that life may have emerged very early on the young Earth, perhaps within a few hundred million years of the end of the epoch of heavy bombardment. I will describe fossil stromatolites, microfossils, and carbon isotope data that are used to explore these questions. Recorded live on 2009 Oct 19 in Room 1005 Smith Laboratory on the Columbus campus of The Ohio State University.