07/24/2014 11:54 am ET Updated Sep 23, 2014

Interview: 99.9% of Species Ever on Earth Are Extinct Now

Richard Ha writes:

The third in my series of expert interviews.

This is Dr. Shane Burgess again, dean of the College of Agriculture and Life Sciences at the University of Arizona, talking this time about how 99.9 percent of all species that ever lived on the earth are now extinct. It's  3 minutes and 20 seconds long. Very interesting; have a listen.