Life on Earth is intended to introduce "younger generations" to biological diversity, "the variety of life on Earth at all its levels, from genes to biogeographic regions, and the ecological and evolutionary processes that sustain it." The encyclopedia's activist perspective and conversational style will appeal to high-school and beginning college students, especially those writing position papers.
Eldredge is curator of paleontology at the American Museum of Natural History (AMNH), and a number of the 60 contributors are AMNH scientists. Most other contributors are associated with major universities and research institutions in the U.S.
Four introductory essays outline the definition, importance, and preservation of biodiversity. Many of the 194 articles are about specific phyla or species (Annelida--the segmented worm, Giant ground sloth, Lagomorpha) or important concepts (Botany, Human evolution, Meteo rology, Soil). Others address issues that will appeal to students and general readers (Ethics of conservation; Medicine, the benefits of biodiversity to; Tourism, ecotourism, and biodiversity). Essays and articles incorporate many tables with sources cited, line drawings, and unremarkable black-and-white photographs. Articles are clearly written, usually define specialized terms, and include bibliographies of books and popular and scholarly periodical articles. An index leads readers to topics mentioned within articles (e.g., deep ecology, ecofeminism, urban sprawl). Rachel Carson is listed in the index as Louise Carson.