This video was shown in Thursday's class: 'Extinction!' is Episode 3 from NOVA's 'Evolution' series (2001). There is a worksheet based upon the video given in class, and which is due on Friday, which I summarize below:
"The video begins with paleontologist Peter Ward hunting for Permian fossils in South Africa's Karoo Desert, and relates ecological pyramids (which are like a 'house of cards') to mass extinctions, which are believed to be rare but important events in the history of life. It then follows the work of American Museum of Natural History researcher Michael Novacek in building the fossil record of small, shrew-like mammals from the Mesozoic, representative of the lineage that will survive the next mass extinction (the K/T event), which will claim the dinosaurs. It concludes with an examination of the role of human activity in accelerating the rate of extinction, with important attention to conservationists like Alan Rabinowitz."
I do not have enough class time to review this with students again, but students who need to review it can either go to Google Video, or watch it embedded here: