The references section lists key works in evolutionary biology, including Hamilton's studies on selfish and spiteful behavior, Price's work on selection and covariance, and Trivers' exploration of reciprocal altruism. Zahavi's contribution discusses the reliability in communication systems and its implications for altruism evolution. The book "Phenotypic Evolution — A Reaction Norm Perspective" by Carl D. Schlichting and Massimo Pigliucci is highly recommended for biologists interested in evolutionary biology. The authors argue that phenotypic plasticity is an integral part of the evolutionary process, not just a peripheral phenomenon. The book provides a historical perspective, an overview of current thinking, and future research directions. It covers the basic concepts of reaction norms and phenotypic plasticity, and presents an analysis of phenotypic evolution using both statistical and mechanistic approaches. While the book includes some areas that may not fit well within the reaction norm perspective, it is provocative and likely to stimulate debate. The authors' view of quantitative genetic analysis as a temporary necessity is criticized, but the book's value lies in its ability to unify disparate data under a common theme. The book "Sperm Competition and Sexual Selection" edited by T. R. Birkhead and A. P. Moller is noted for its significant contributions to evolutionary biology. It highlights the importance of sperm competition as a powerful evolutionary selection pressure, reflecting Parker's (1970) influential idea. The field of sperm competition is described as diverse and rapidly expanding, with ongoing advancements in understanding its evolutionary consequences.The references section lists key works in evolutionary biology, including Hamilton's studies on selfish and spiteful behavior, Price's work on selection and covariance, and Trivers' exploration of reciprocal altruism. Zahavi's contribution discusses the reliability in communication systems and its implications for altruism evolution. The book "Phenotypic Evolution — A Reaction Norm Perspective" by Carl D. Schlichting and Massimo Pigliucci is highly recommended for biologists interested in evolutionary biology. The authors argue that phenotypic plasticity is an integral part of the evolutionary process, not just a peripheral phenomenon. The book provides a historical perspective, an overview of current thinking, and future research directions. It covers the basic concepts of reaction norms and phenotypic plasticity, and presents an analysis of phenotypic evolution using both statistical and mechanistic approaches. While the book includes some areas that may not fit well within the reaction norm perspective, it is provocative and likely to stimulate debate. The authors' view of quantitative genetic analysis as a temporary necessity is criticized, but the book's value lies in its ability to unify disparate data under a common theme. The book "Sperm Competition and Sexual Selection" edited by T. R. Birkhead and A. P. Moller is noted for its significant contributions to evolutionary biology. It highlights the importance of sperm competition as a powerful evolutionary selection pressure, reflecting Parker's (1970) influential idea. The field of sperm competition is described as diverse and rapidly expanding, with ongoing advancements in understanding its evolutionary consequences.