Animal evolution has always been at the core of Biology, but even today many fundamental questions remain open. The field of animal 'evo-devo' is leveraging recent technical and conceptual advances in development, paleontology, genomics and transcriptomics to propose radically different answers to traditional evolutionary controversies.

Part 1. Animal Origins.- Chapter 1. 1. The protistan cellular and genomic roots of animal multicellularity.- Chapter 2. Exceptionally preserved Cambrian fossils in the genomic era.- Part 2. The developmental view of animal evolution.- Chapter 3. Comparative embryology as a way to understand evolution.- Chapter 4. How do developmental programs evolve?.- Chapter 5. How do morphological novelties evolve? Novel approaches to define novel morphologies.- Chapter 6. Germ layer evolution: using novel approaches to address a classic evolutionary embryological problem.- Chapter 7. Origin and evolution of nervous systems.- Part 3. The genomic view of animal evolution.- Chapter 8. Boosting macroevolution: genomic changes triggering qualitative expansions of regulatory potential.- Chapter 9. How do gene networks promote morphological evolution?.- Part 4. Theoretical approaches to animal evolution.- Chapter 10. How does modularity in the genotype-phenotype map shape development and evolution?.- Chapter 11. Can we compute the embryo?.- Chapter 12. What is a biological individual?.