April 6, 2001, Hour One: Human Cloning April 6, 2001, Hour Two: Dark Energy / Threat of Bioterrorism April 13, 2001, Hour One: Space Shuttle Past and Future April 13, 2001, Hour Two: Intelligence Technology / Industrial Ecology April 20, 2001, Hour One: Oceans and Fisheries Update April 20, 2001, Hour Two: Endangered Species and Biotechnology April 27, 2001, Hour One: Mars Exploration / Feathered Fossil Find April 27, 2001, Hour Two: Preserving Digital Information