Full Of Life

Sierra, Nov, 1998

The 17 "megadiversity" countries named above contain more than two-thirds of Earth's biological resources. Conservation International determined the rankings based on numbers of endemic species (species that don't occur elsewhere) and overall species diversity, among other factors. No landlocked countries made the top 17, nor did any lacking tropical rainforest.

The United States, one of only two developed nations on the list, made the cut partly because of its climatic variety--from polar regions in Alaska to tropical rainforest in Hawaii. Among the riches within its borders are 18,000 species of plants and 346 species of mammals.