Intended for the nonscientist, this welcome update to the first edition (1999) offers 64 new essays on current topics, reflecting the swift pace of discovery in the field. Of the 172 original entries, 7 have been dropped because they were no longer relevant and 26 were completely rewritten. Some 131 of the entries were revised and updated. Overall, the revised edition has increased in number of essays as well as in word length, consisting of 233 signed essays from Aggression to XYY Syndrome. This edition also features 25 new mini-essays that offer treatment of noteworthy or current subtopics appended to main entries.
Each volume starts with an alphabetical list of contents. The essays all follow a similar format. Each begins with top matter that lists "Field of Study" offering one or more subdisciplines under which the topic falls. This is followed by "Significance," which provides a definition of the topic and a summary of its importance. Next are definitions of "Key Terms." Headings break the main body of each essay into clearly defined subtopics. The articles conclude with see also references as well as a list of further reading. All of the individual essays' bibliographies are new or updated. About half of the essays include "Web Sites of Interest" directing users to Web sites of government agencies, professional or academic societies, support organizations, and a few relevant personal URLs. Basic black-and-white photographs and charts supplement the text.
The set concludes with several appendixes. The biographical dictionary of important geneticists, time line of major developments in genetics, glossary, and bibliography have been revised. Two new appendixes, a list of Nobel prizes for discoveries in genetics and a list of Web sites, have been added. To help users locate subjects according to area of study, a category index, a personages index, and a comprehensive subject index are included at the end of the second volume. There is no index in volume 1.
Macmillan's Genetics (2002) has a more appealing layout and better graphics and is more suited to the student with no background in the topic. World of Genetics (Gale, 2001) includes more articles (800) although they are generally shorter in length. The Salem set provides clear explanations and is recommended for college and high-school libraries as well as any public library that has a large science collection.