1. Speciation

2. Biological Species Concept Population that can interbreed to produce viable and fertile offspring

3. Eastern Meadowlark Western Meadowlark Biological Species Concept Cannot breed, different songs, different behaviors

4. Speciation Formation of a new species

5. How does Speciation occur? - Gene pools become separated - Populations become reproductively isolated Reproductive Isolation Biological barriers that prevent members from producing viable and fertile offspring

6. Reproductive Isolation Pre-zygotic (before the zygote)

7. Habitat Isolation 2 species, 2 different habitats within same area Rarely cross paths

9. Temporal Isolation Eastern Spotted Skunk Western Spotted Skunk Reproduce late winter Reproduce late summer Breed at different times (day/season/year) Cannot mix gametes

10. Behavioral Isolation Courtship rituals that are unique to breeding success

12. Mechanical Isolation Morphological differences that prevent mating

13. Gametic Isolation Purple Sea Urchin Red Sea Urchin Sperm of #1 not able to fertilize egg of #2 Sperm cannot survive, cannot penetrate egg

14. Reproductive Isolation Post-zygotic (after the zygote) Hybrid Equine

15. Zebroid or Zorse - sterile Viable (able to survive) Infertile (not able to reproduce)

16. Zedonk, Zebrass - sterile

17. Offspring = Mule = sterile Horse Donkey

18. Offspring = Hinny = sterile Horse