1. 23.1 Relationships among phyla

2. 23.2 Modularity of development: morphogenetic fields

3. 23.3 Modularity of development: enhancers

4. 23.7 The same set of instructions forms the nervous systems of both protostomes and deuterostomes

5. 23.8 Autopods of chicken feet and duck feet are shown at similar stages

6. 23.9 Hox gene expression and morphological change in crustaceans (Part 1)

7. 23.9 Hox gene expression and morphological change in crustaceans (Part 2)

8. 23.10 The expression of Ubx and abdA (green) in the thoracic segments of different types of crustaceans

9. 23.11 Model for the evolution of the feather by changes in the pattern of Bmp2 and Shh expression

10. 23.12 Loss of limbs in snakes

11. 23.13 GIS analysis of gene activity in the formation of the first set of cusps in mouse and vole molars

12. 23.14 Basic model for cusp development in mice and voles (Part 1)

13. 23.14 Basic model for cusp development in mice and voles (Part 2)

14. 23.15 Allometry and modularity in the vertebrate eye

15. 23.16 Neural crest cell migration patterns in lampreys and gnathostomes

16. 23.17 Correlation between beak shape and the expression of Bmp4 in Darwin’s finches

17. 23.18 Allometric growth in the whale head

18. 23.19 Changes in Ubx protein associated with the insect clade in the evolution of arthropods

19. 23.20 Co-option of signal transduction pathways in the formation of butterfly eyespots

20. 23.21 Expression of a frog Distal-less gene in the mouse

21. 23.22 Evolution of the mammalian middle ear bones from the reptilian jaw (Part 1)

22. 23.22 Evolution of the mammalian middle ear bones from the reptilian jaw (Part 2)

23. 23.24 Extra cervical ribs are associated with childhood cancers (Part 1)

24. 23.24 Extra cervical ribs are associated with childhood cancers (Part 2)

25. 23.25 Mechanism for the bottleneck at the pharyngula stage of vertebrate development

26. 23.27 An emerging evolutionary synthesis