1. E V O L U T I O N

2. SPECIATION : the development of a new species Sometimes the variation among organisms is too great; eventually they could become separate species

3. GEOGRAPHIC ISOLATION : two populations are separated by geographic barriers such as rivers, mountains, bodies of water, etc. Ex: Albert Squirrel and Kaibab Squirrel BEHAVIORAL ISOLATION : two populations behave too differently to co-exist Ex: Eastern Meadowlarks & Western Meadowlarks have different mating songs

4. TEMPORAL ISOLATION : two populations reproduce at different times Ex: flowers with different blooming seasons REPRODUCTIVE ISOLATION : the two populations cannot interbreed or produce fertile offspring; gene pools are too different Ex: Horses + Donkeys = Mules

5. PANGAEA : a proposed supercontinent that formed over 300 million years ago Began separating 200 million years ago

6. proposed ancestor on Pangaea Ostriche Africa Emu Australia - flightless - fast; agile - use wings as defense and mating Believed they arose from a common ancestor on Pangaea, then became separate species after many years of isolation Rhea South America

7. DIVERGENT EVOLUTION : evolution of different features from similar lineages

8. DIVERGENT EVOLUTION : evolution of different features from similar lineages

9. DIVERGENT EVOLUTION : evolution of different features from similar lineages

10. DIVERGENT EVOLUTION : evolution of different features from similar lineages Divergent Evolution and Homologous Structures show how certain species may have come from the same ancestor

11. CONVERGENT EVOLUTION : evolution of similar features from different lineages

12. CONVERGENT EVOLUTION : evolution of similar features from different lineages

13. CONVERGENT EVOLUTION : evolution of similar features from different lineages

14. CONVERGENT EVOLUTION : evolution of similar features from different lineages

15. CONVERGENT EVOLUTION : evolution of similar features from different lineages Convergent Evolution and Vestigial Structures show how different species adapt to similar environments

17. DIVERGENT same becomes different CONVERGENT different becomes same