As the co-formulator with Charles Darwin of the theory of biological evolution via natural selection, naturalist Alfred Russel Wallace (1823-1913) argued that plant and animal species develop throughout organic history. Wallace focused special attention on the diversity of tropical life forms and became acutely aware of the adaptive relationship between each species and its particular environment: an ongoing relationship that is necessary for survival and reproduction. After amassing empirical evidence from the Malay Archipelago, Wallace wrote Island Life (1881) in order to document the dynamic realtionship between organisms and their climatic habitats. Anticipating our present concern with both endangered species and vanishing environments, Wallace's ecological studies helped substantiate the fact of evolution. This book is an excellent example of long-term research and the far-reaching insights such scientific projects hold for understanding and appreciating the evolving life on Earth.