This book attempts a broad theoretical synthesis within the field of sociology and its closely allied sister discipline of anthropology. It draws together what the author considers the best of these disciplines' theoretical approaches into a synthesized theory called Darwinian conflict theory. This theory, in the most general sense, is a synthesis of the tradition of economic and ecological materialism and conflict theory stemming from Marx, Marvin Harris, and the tradition of biological materialism deriving from Darwin. The first half of the book is taken up with critiques of existing theoretical approaches; this then leads to the full elaboration, in formal propositional form, of synthetic theory. The second half of the book lays out the large amount of evidence, both qualitative and quantitative, that supports the synthesized theory.