Fungi are among the most versatile and diverse groups of organisms in their morphology, life cycles, and ecology. This has provided endless fasci­ nation and intrigue to those who have studied fungi, but it has also made it difficult to understand fungal biology from the perspective of the broader fields of evolution, ecology, genetics, and population biology. That is changing. Details of fungal biology have been elucidated at an exciting pace, increasingly allowing us to understand fungi on the bases of general biological principles. Moreover, many who study fungi have lately emulated some of the great mycologists and plant pathologists of the early years in applying an insight born of broad perspective. This change has been particularly apparent in fungal population biology. In this book, many of those at the forefront of that change summarize, integrate and comment on recent developments and ideas on populations of fungi. By taking a broad perspective, they show how new information on fungi may contribute to concepts and ideas of biology as a whole. Just as important, they contribute to further invigoration of fungal population research by illuminating mycology with new ideas and concepts, derived in part from other biological fields.