http://www.pbs.org/wgbh/nova/nature/dogs-decoded.html . above is a link, which is no longer streaming, but SOooo worth a watch. If you ever see a Nova special going by, called "Dogs Decoded" do stop and record THAT show! or link above has option to purchase the documentary. . Just an amazing video, that all dog lovers will so so enjoy so much. . Why have dogs learned to bark, but not wolves? Can YOU understand the variations of a dog's bark? (know what the dog is "saying"?) Why DO we love dogs so much? How did this dog/human relationship ever get started? The genetics of behavior, specifically, of aggression vs friendly. Did dogs actually help human species survive? Can dogs read human emotions? What do dogs while interacting with humans but not with other dogs? just lots of fascinating lil things to think about. . OH! OH!!! Here is the video available for streaming: you CAN watch it right now! yay! http://topdocumentaryfilms.com/dogs-decoded/ . . . DO WATCH! click on this video, you WON'T be able to stop watching it. Make some popcorn, get your sweetie, click for "full screen" and then, you'll probably think about this video for a long long time afterwards...everytime your dog barks, ha ha!!