Scott Gilbert's Developmental Biology has metamorphosed into the Gilbert and Barresi Developmental Biology. Even the axes have changed. The book has a new phenotype, which should make it easier to customize one's developmental biology course to the needs and interests of today's students. Michael Barresi brings his creativity and expertise as a teacher and as an artist of computer-mediated learning to the book, integrating the print with electronic interviews, videos, and tutorials. He also brings to the book new ideas in education, such that there are shorter chapters, more websites, and alternative ways of teaching animal development. There is also more emphasis on stem cells, which are brought to the front of the book; sex determination and gametogenesis, instead of being near the end of the volume, are now up front, as well. There are several new modes of teaching that the new Gilbert and Barresi textbook now makes accessible. The videos explaining development-as well as Mary Tyler's laboratory manual and Vade Mecum-are fully integrated into the book, and several other valuable new elements have been added: - Opening Question and Photo: Inviting the student into the text and engaging curiosity, each chapter begins with a photograph and short question that will be revisited throughout the chapter and in a summary paragraph at the end. - The Punchline: More than a chapter outline, this opening paragraph provides the student with a quick overview of the big principles that will be exemplified in the chapter. - Dev Tutorials: A teacher you can take with you, each chapter will be accompanied by a professionally produced video tutorial by the authors that reinforce the key concepts. Each video is also supplemented with an in-class case study activity. - Watch Developments: Putting concepts into action, these informative videos show real-life developmental biology processes. - Developing Questions: Building on topics explained in the text.