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Gene duplication and divergence:

head limb A-P. Gene duplication and divergence:. eye. Metazoan phylogeny:. G enome duplication correlates with increased complexity: Hox as a case study. Hox genes specifies regional identity along the primary body axis.

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Gene duplication and divergence:

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  1. head limb A-P Gene duplication and divergence: eye

  2. Metazoan phylogeny:

  3. Genome duplication correlates with increased complexity: Hox as a case study. • Hox genes specifies regional identity along the primary body axis. • Arrangement along the chromosome correlates with A-P expression.

  4. Hox genes & segmental identity:

  5. Hox genes & segmental identity:

  6. Hox genes & segmental identity:

  7. Hox genes & segmental identity:

  8. Hox genes & segmental identity:

  9. Hox genes & segmental identity:

  10. Genome duplication correlates with increased complexity: Hox as a case study. • Expansion of the Hox cluster is associated with increased complexity along the A-P axis. • Achieved via tandem and whole genome duplications.

  11. orthologous paralogous

  12. complexity

  13. complexity wnt

  14. complexity

  15. complexity

  16. complexity

  17. complexity

  18. 25,000 spp. • 30,000 spp. • 10,000,000+ spp. Metazoan phylogeny: • 1. Characterized by increased genetic AND morphological complexity. • 2. Not increased diversity! • 3. Evolutionary diversification within phyla occurred in the context of shared genetic tools. How??

  19. How the turtle got it’s shell • Sudden appearance in the fossil record. • Relatively rapid evolution. • Relatively simple shift in development.

  20. 1. 2. How the turtle got it’s shell: carapace

  21. How the turtle got it’s shell: carapace

  22. How the turtle got it’s shell: carapace

  23. How the turtle got it’s shell: carapace

  24. fgf10 How the turtle got it’s shell: carapace AER Carapical ridge - key innovation for novel turtle rib patterning

  25. Bmp2 Bmp2 Noggin Bmp2 How the turtle got it’s shell: carapace Bmp2 Heterotopy - Shift in spatial location.

  26. How the turtle got it’s shell: carapace • Two step process: • Unlike in other vertebrates, rib bone cells (sclerotome) migrate laterally toward the carapical ridge (CR) - directed by fgf10. • In this new environment (with no Noggin), ribs fuse via expanded Bmp signaling. • Heterotopy provides an explanation for the rapid evolution of the turtle shell.

  27. The beak of the fish??

  28. Lake Victoria Lake Tanganyika Lake Malawi Cichlids evolve extremely rapidly: ~100,000 yrs > 500 spp. ~10 myrs > 300 spp. ~1 myrs ~ 1000 spp.

  29. LM LV LT Screw beaks, fish faces are way cooler…

  30. Cichlids have evolved along a conserved eco-morphological axis: 10 MY 1 MY 0.1 MY

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