Summary: No science has ever been done without an indissoluble link between theory and fact: facts are colored by the theoretical spectacles on puts on, just as much as theory is shaped by the results of empirical observation. Theoretical biology is a broad and rapidly growing field where this link is actually explored with passion and discipline. The chapters of this book have been chosen to give the student of theoretical biology the flavor of current exciting research in the field. The eleven chapters are divided into three broad sections: the emergence of life, the development of the individual, and the study of the interaction between individuals and species.