In the late 1970s, ethnobotanist and conservationist Dr. Mark Plotkin traveled into the jungles of the Amazon to study the botany of indigenous cultures and find plants with healing powers. What started as an adventure turned into a calling as he saw how quickly the plants and the people of the Amazon were being crushed by progress. In 1995, he and his wife, Liliana Madrigal, cofounded the Amazon Conservation Team (www.amazonteam.org), a nonprofit whose efforts have protected millions of acres of rainforests. By playing a principal role in the IMAX film Amazon and through his books like Tales of a Shaman's Apprentice (now in its 21st printing), Plotkin, 48, has helped millions appreciate the value of the forest and its people.

"Twenty years ago I set out to learn as much as I could about the way the Indians of the Amazon used forest plants before the knowledge disappeared.

"Few of the 120 prescription drugs on the market using plant derivatives as active ingredients were actually 'discovered' by university-trained scientists. Indians beat us to finding healing powers in many plant chemicals, including those found in quinine, aspirin, taxol, and various cancer drugs.

"I believe cures for some 'incurable' diseases [cancer, AIDS, diabetes] will come from the Amazon rainforest. The region is without equal - it teems with more plant life than any place on the planet. And more insect life. To survive millions of years of entomological onslaught, the plants have become sophisticated chemical warriors. Yet we've only closely studied five percent of the region's 80,000 plant species. Among those unstudied species we will find medicines, foods, fibers, pesticides, and chemicals of immense value.