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