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.