The basin of the Amazon river is home to the world's richest assortment of life - including some 20 million different species. In fact, it's estimated the Amazon contains one quarter of all the plants on Earth. Scientists believe the region's incredible biodiversity can be tapped to find cures for diseases modern medicine has been unable to conquer. For 15 years, ethnobotanist Dr. Mark Plotkin has worked with shamans from South and Central American tribes to learn more about the medicinal use of native plants and animals. He and his work are featured in the new Oscar-nominated IMAX movie "Amazon" which opens today at the Minnesota Zoo.