Traces the history of man's discoveries about evolution, covering both the mechanisms of evolution and examples of natural selection.

Profiles birds, fish, mammals, insects, and amphibians in alphabetical order, providing information on each animal's physical characteristics, behavior, and habitat.

On cover: Assessing the greenhouse threat. Examines the greenhouse effect, focusing on its complex causes and potential impact on global weather, ecology, and economy.

Describes Merlin Tuttle's interest in bats, his study of them in their natural habitat, and his work to protect them through such efforts as the organization he founded, Bat Conservation International.

Explains the importance of wildlife and the ways in which people are trying to save various species in North America.

Introduces readers to the life and behavior of penguins.

Describes the behavior of three species of small blood-eating bats of the leafnose family found in Mexico, Central America, and South America.

A biography of William Clark's personal slave, who provided invaluable assistance to the Lewis and Clark Expedition.

Text and explanatory photographs describe petroleum and its uses, examine the harmful effects of oil spills, and discuss how such environmental disasters can be cleaned up or prevented.