Explains various theories about how dramatic changes in the earth's surface could have caused periodic mass extinctions, with an emphasis on the disappearance of the dinosaurs.
Explains what species are, how they become extinct, and the effect of extinction on the ecology, and surveys endangered species of plants and animals and possible solutions.
Explains what species are, how they become extinct, and the effect of extinction on the ecology, and surveys endangered species of plants and animals and possible solutions.