Author Isaac Asimov joins NOVA in the retelling of the remarkable story of the discovery of the structure of DNA. James Watson and his ex-colleague Francis Crick exchange memories of the events which led to their winning the race for the structure of the gene.

Each Sunday edition of the New York Times consumes 153 acres of trees. The paper packs, napkins, paper cups and packing used by McDonald's gobble up 315 square miles of trees every day. NOVA asks if, at this rate, trees can remain a renewable resource.