The Structure of Evolutionary Theory The Structure of Evolutionary Theory The Structure of Evolutionary Theory (2002) is Harvard paleontologist Stephen Jay Gould's technical book on macroevolution and the historical development of evolutionary theory. The book was twenty years in the making, published just two months before Gould's death. Aimed primarily at professionals, the volume is divided into two parts. The first is a historical study of classical evolutionary thought, drawing extensively upon primary documents; the second is a constructive critique of the modern synthesis, and presents a case for an interpretation of biological evolution based largely on hierarchical selection, and the theory of punctuated equilibrium
Zero-Force Evolutionary Law Zero-Force Evolutionary Law The Zero-Force Evolutionary Law, or ZFEL, is a theory proposed by Robert Brandon and Dan McShea regarding the evolution of diversity and complexity. Brandon and McShea define diversity and complexity in terms of variation, diversity being variation between organisms and complexity being variation among parts within an organism. McShea had previously defined a part as "a system that is both integrated internally and isolated from its surround," giving the digestive tract, epidermis, and skeleton, as examples. As an analogue to the theory of relativity, the theory has a special and general formulation. The special formulation states "in