1. Set up Cornell Notes on pg. 29
Topic: 11.5 Speciation Through Isolation
Essential Question:
How did geographic isolation affect the diversity Darwin observed in the Galapagos finches?
Why are the flash patterns of fireflies considered to be behavioral isolation?
11.5 Speciation Through Isolation
2.1 Atoms, Ions, and Molecules
How did geographic isolation affect the diversity Darwin observed in the Galapagos finches?
Why are the flash patterns of fireflies considered to be behavioral isolation?

2. KEY CONCEPT New species can arise when populations are isolated.

3. If gene flow between two populations stops for any reason, the populations are said to be isolated
As populations adapt to their environment, their gene pools change
Changes add up over many generations
Populations become more and more different
Start to look and behave differently from one another

4. Reproductive isolation occurs when members of different populations can no longer mate successfully with one another
It is the final step of becoming separate species

5. Speciation is the rise of two or more species from one existing species due to reproductive isolation.

6. Populations can become isolated in several ways.
1. Behavioral isolation- is caused by differences in courtship or mating behaviors
Changes in chemical scents, mating dances, songs or signals can prevent mating
Ex: Fireflies produce patterns of flashes that attract their mates. Over 2000 species of FF are isolated based on the patterns of flashes

7. 2. Geographic isolation- involves physical barriers that divide a population into two or more groups
Isthmus of Panama formed 3 million years ago
Ex: snapping shrimp on each side will not mate with one another they snap at each other instead

8. Grand Canyon speciation of squirrels due to geographic isolation

9. 3. Temporal isolation- when timing prevents mating/reproduction between populations
Ex: The Monterey Pine and the Bishop pine have different pollination periods. (February/April)
Bishop pine

10. Field crickets’ reproductive isolation due to temporal isolation

11. Create your own new species!
Pick any existing animal
Please chose one of the three ways speciation occurs
Behavioral
Geographic
Temporal
Using your imagination, please draw a diagram of how your chosen species might diverge into two new closely related species
Keep it realistic! Ex: Humans can’t become unicorns

14. VIDEO CLIPS
Humming bird mating dance
Bird mating dances
Bird courtship dance