4.1

1. Metazoa Protozoa 4.1

2. Spiral Cleavage Radial Cleavage Eight-cell stage Four-cell stage Two-cell stage (cleavage begins) Fertilized egg 4.2

3. Cnidaria: Aurelia Annelida: Eupomatus Cephalochordata: Brachiostoma 4.3

4. Medial Posterior Anterior 1 2 3 4 5 6 7 8 9 10 11 12 13 a-1 a-13 b-1 b-9 Vertebrates c-4 c-13 d-1 d-13 Branchiostoma floridae (Chordata) 1 10 Drosophila melanogaster (Arthropoda) lab pb Dfd Ser Antp Ubx Abd A Abd B Drosophila pseudoobscura (Arthropoda) Tribolium castaneum (Arthropoda) mxp Dfd Cx Ptl Utx A Extra urogomphi Artemia (Arthropoda) AfDfd AfAntp AfabdA AfSer AfUbx Ctenodrilus serratus (Annelida) 1 8 Caenorhabditis elegans (Nemertina) lin-39 (ceg-15) ceh-13 mab-5 egl-5 (ceg-11) Schistosoma mansoni (Platyhelminthes) lab ?pb Dfd Antp Chlorohydra viridissima (Cnidaria) Cnox1 Cnox2 antpC 4.4

5. old lab pb Dfd Scr Ubx AbdB eve ems 4.5 Frog AbdB (Amphibian) Amphioxus pb (Urochordate) Mouse Ubx (Mammal) The Zootype Fruit fly Ubx (Insect) Leech Ubx (Annelid) C. elegans Ubx (Nematoda)

6. 4.6

7. 4.7 2.00 1.75 1.50 Fitness 1.25 1.00 0.75 1973 -0.2 -0.1 0.0 1983 0.1 0.2 1993 2003 Year Plasticity

8. 4.8 Changes in Structural genes Natural selection acts on new phenotypic traits Reproductive isolation Phenotypic changes Changes in diet, daily patterns of activity, social interactions, etc. New environments are entered Original phenotypes

9. 4.9 Progenesis Peramorphosis Sexual maturity occurs earlier in D than in A. D develops new stages not present in A. Neoteny Acceleration Juvenile development is retarded in D, relative to A. Juvenile development is accelerated in D, relative to A. Postdisplacement Predisplacement Onset of development is delayed in D, relative to A. Onset of development occurs earlier in D, relative to A. Dwarfism Gigantism Paedomorphosis Peramorphosis D smaller than A in body size. D larger than A in body size. D adult similar to juvenile A. D develops new stages not present in A. Same morphology Different body size Different morphology Different body size HETEROCHRONY

10. 4.10 (a) (b)

11. 4.11 (a) Paedomorphosis (b) Peramorphosis Progenesis Hypermorphosis A B A B C D Descendant A B C A B C Ancestor Neoteny Acceleration A B A B C D Descendant A B C A B C Ancestor Postdisplacement Predisplacement A B B C D Descendant A B C A B C Ancestor Fertilization Sexual maturity Fertilization Sexual maturity

12. 4.12 600 400 200 100 60 Horn Length (mm) 40 20 10 8 6 4 400 1000 Basilar Length of Skull (mm)

13. 4.13 Behavior Artificial selection target • Early response to • external stimuli • Delayed sensitive • period for • socialization Tamability Physiology Hormones Neurotransmitters • Early sexual • maturation • Longer breeding • season • Larger litter size Correlated changes Genes Morphology Developmental program (simplified) • Floppy ears • Shorter or rolled tail • Short legs • Depigmentation

14. 4.14 S1 30 20 10 0 S4 30 20 Attack Frequency 10 0 S13 30 20 10 0 40 80 160 180 220 260 Age (Days)

15. 4.15 (e) (c) (d) (a) (b)

16. 4.16 Procencephalon Diencephalon Telencephalon Mesencephalon Rhombencephalon A4 A3 A2 A1 Hox A Genes

17. (a) (b) 4.17

18. 4.18 Chemical and morphological analyses of the CNS Behavioral testing Treatment duration (e.g., 30 days) Enriched environment Impoverished environment Randomly assigned Weaned at about 21-24 days of age Pairs of littermates