During the last decade the well-established tools of statistical physics have been successfully applied to an increasing number of biological phenomena. It is a fruitful approach to systems characterized by fluctuations and/or a large number of very similar units, and such systems are common in biology, whether it be the individuals in the codons of a genetic code or the behavioral responses of macromolecules to thermal fluctuations. This book is thus able to cover a wide range of phenomena, including fractal pattern formation, group motion in organisms from bacteria to humans, or the...