Wednesday, April 27, 2005
Did super greenhouse conditions cause mass extinctions in the past?
There were five "major" mass extinctions (>50% species death) and at least eleven more minor mass extinctions during the last 550 million years. In the past decade it has been assumed that most or even all of these die offs were the result oflarge body impact on the Earth. However, much new evidence now suggests otherwise. In this talk I will concentrate on new isotopic and paleontological evidence of sudden global heating and drops in oxygen levels as a possible cause.
Peter Ward is a Professor in the Biology Department at the University of Washington.