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More Selection

More Selection. Divergent evolution. Divergent evolution. Similar organisms evolve from a common ancestor. Did these two species evolve from a common ancestor?. Convergent evolution. Large front paws Small eyes Tapered nose. Large front paws Small eyes Tapered nose. Different ancestor.

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More Selection

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  1. More Selection

  2. Divergent evolution

  3. Divergent evolution • Similar organisms evolve from a common ancestor

  4. Did these two species evolve from a common ancestor?

  5. Convergent evolution • Large front paws • Small eyes • Tapered nose • Large front paws • Small eyes • Tapered nose Different ancestor

  6. Convergent evolution Organisms from different evolutionary lineages may evolve analogous adaptations to similar environments.

  7. Types of Selection

  8. Stabilizing selection

  9. Stabilizing selection

  10. Directional selection

  11. Disruptive selection

  12. Disruptive selection • Extreme traits are favored • Population divided into two distinct groups

  13. Sexual selection Superb bird of paradise mating dance video

  14. Sexual selection • Acts on organism’s ability to obtain or successfully reproduce with a mate. • Often powerful enough to produce features that are harmful to survival (i.e. attract predators) Can lead to extreme differences in male/female phenotypes!

  15. Artificial Selection

  16. ?

  17. Teosinte modern corn • Wild grass from Mexico and Central America • Can pollinate cultivated corn to produce viable seeds • What selective pressure did humans put on teosinte to develop modern corn?

  18. What about animals?

  19. Dog breeding • Wolf  dog ancestor  modern breeds • Selected traits for hunting, companionship

  20. Designer dogs?

  21. Questions?

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