Video of Peter Ward lecture on Earth's mass extinctions

Here is the link to his lecture.

Peter Ward is a paleontologist.  I have been reading his books for a decade or so, he focuses on Mass Extinctions (Dinosaur die off is the Mass Extinction most people are familiar with) the study of which is a hobby of mine.

Here is a short bio of his from the University of Washington webite, he is faculty there.

Here is a list of some of his books Peter Ward books