This work provides a unified theory that addresses the important problem of the origin and maintenance of genetic variation in natural populations. The author uses his background in biomathematics, genetics and evolutionary research to present an overview of the causes of molecular evolution.

"John Gillespie has thought harder than anyone else about the subtleties of the ways in which natural selection can bring about variation and evolution at the molecular level, and he has an enviable command of the theoretical and empirical literature on molecular evolution. [His book] deserves the careful attention of everyone interested in this field....Well written and informative." --Science "I like this book, and it is valuable to have many elements of the debate under one cover....This work will begin to counter the influence that defenders of the neutral theory have enjoyed over the past decade....A timely contribution which will promote interest in the study of adaptation at the molecular level." --Nature "Presents a unified theory that tackles the important current problem of the origin and maintenance of the genetic variation found in natural populations. Consideration of the great advances made in the discipline of population genetics makes this of interest to many readers." --Choice "Gillespie provides the first thorough assessment of the success of selectionist and neutralist arguments in explaining the data on genetic variation." --The Times Higher Education Supplement "Examines the whole question of molecular evolution, with reference to both experimental and mathematical approaches. The layout of the book allows the three parts to be read independently, which may be useful for those not mathematically inclined....Recommended for geneticists, biologists, and evolutionary theorists." --Animal Breeding Abstracts "Students in molecular evolution will welcome this book....An initial attempt to introduce realistic assumptions into current models of molecular evolution and contains many stimulating and often provocative ideas." --Laurent Excoffier (University of Geneva), Human Biology "John Gillespie has thought harder than anyone else about the subtleties of the ways in which natural selection can bring about variation and evolution at the molecular level, and he has an enviable command of the theoretical and empirical literature on molecular evolution. [His book] deserves the careful attention of everyone interested in this field....Well written and informative." --Science "I like this book, and it is valuable to have many elements of the debate under one cover....This work will begin to counter the influence that defenders of the neutral theory have enjoyed over the past decade....A timely contribution which will promote interest in the study of adaptation at the molecular level." --Nature "Presents a unified theory that tackles the important current problem of the origin and maintenance of the genetic variation found in natural populations. Consideration of the great advances made in the discipline of population genetics makes this of interest to many readers." --Choice "Gillespie provides the first thorough assessment of the success of selectionist and neutralist arguments in explaining the data on genetic variation." --The Times Higher Education Supplement "Examines the whole question of molecular evolution, with reference to both experimental and mathematical approaches. The layout of the book allows the three parts to be read independently, which may be useful for those not mathematically inclined....Recommended for geneticists, biologists, and evolutionary theorists." --Animal Breeding Abstracts "Students in molecular evolution will welcome this book....An initial attempt to introduce realistic assumptions into current models of molecular evolution and contains many stimulating and often provocative ideas." --Laurent Excoffier (University of Geneva), Human Biology