What makes a bird a bird and a frog a frog? The key to understanding the mechanisms that generate biological form and diversity lies in a new and rapidly growing field, termed "evo-devo," that represents a synthesis of evolution and development. This course, designed specifically for sophomores, aims to explore evo-devo in detail by building on material introduced in Biology 102. Using readings from the primary literature, the course will consider topics such as how the modification of developmental mechanisms can create novel traits, why some traits are resistant to change, how the determination of shared ancestral traits differs from those that rise independently, and how ecological considerations impact development to modulate evolutionary change. Format: tutorial. Requirements: after an initial group meeting, students meet weekly with a tutorial partner and the instructor for an hour each week. Each student will write and present orally a five-page paper every other week on the readings assigned for that week. In alternate weeks the students will question and critique the work of their colleague. Evaluation will be based on five 5-page papers, tutorial presentations, and the student's effectiveness as a critic. Prerequisites: Biology 202. Enrollment limit: 10 (expected: 10). Preference given to sophomores.