Lately, my favorite thing to watch on TV has been Ken Burn's National Parks: America's Best Idea series. Sometimes I'm lucky enough to catch it when it's actually on TV, but many days I end up watching it On Demand. Last night, the only episode On Demand was one I've already seen, so I scanned through the other History & Nature shows on the Comcast On Demand menu and saw that there was something from PBS Nova called "Megabeasts' Sudden Death." I opened it to read the description and was so incredibly excited! It was an episode about the new theory of what killed off the megafauna (like mammoth, mastodon, giant sloth) at the end of the Pleistocene epoch, right around the time of the last ice age. If you recall, I wrote an entire research paper on this subject for my English class earlier this year, so I was very eager to watch the show. Short-faced bear and other animals, with mastodons in the background. It focused on the new evidence that a com