All the key principles that students need to know, underpinned by experimental evidence and molecular detail. The process of biological development is an amazing feat of tightly regulated cellular behaviours - differentiation, movement, and growth - powerful enough to result in the emergence of a highly complex living organism from a single cell: the fertilized egg. With cutting edge science and custom drawn figures and animations, the new edition of Principles of Development clearly illustrates the universal principles that govern this process of development in a clear, succinct, and accessible style.