Peter J. Bryant, Professor of Developmental and Cell Biology at the University of California, Irvine, provides this hypertext book as a learning aid for his Biological Conservation class. It is an excellent, comprehensive introduction to the topic. Divided into sixteen understandable chapters, it covers such topics as the history of life, depletion and extinction from over-exploitation, exotic introductions, and deforestation, among others. The content is supported by illustrations, photos, charts, and a webliography for each chapter (a work in progress which is also available in full at the end of the book). However, the features that add the greatest value to the site are the well thought out hyperlinks to other relevant resources. There are literally hundreds of these; they combine with the original content of the site to form a powerful resource for undergraduate students.