Evolutionary Phonology is a new theory of sound patterns which synthesizes results in historical linguistics, phonetics, and phonological theory. In this groundbreaking book, Juliette Blevins explores the nature of sound patterns and sound change in human language over the past 7000-8000 years. She presents a new approach to the problem of how genetically unrelated languages, from families as far apart as Native American, Australian Aboriginal, Austronesian, and Indo-European, can often show similar sound patterns, and also tackles the converse problem of why there are notable exceptions to most of the patterns that are often regarded as universal tendencies or constraints. A formal model of sound change is presented that integrates phonetic variation and patterns of misperception to account for attested sound systems, without reference to markedness or naturalness within the synchronic grammar.