Book excerpt: Finally, an eBook version of this now classic textbook has become available. Largely based on the 6th edition, published in 2000, this version is competitively priced. Written by well-known ecologist Eric R. Pianka, a student of the late Robert H. MacArthur, this timeless treatment of evolutionary ecology, first published in 1974, will endure for many decades to come. Basic principles of ecology are framed in an evolutionary perspective.