1. Chapter 17.3 (Pgs. 494-497): The Process of Speciation

2. Species
A population or group of populations that can interbreed and produce fertile offspring
The formation of new species is called speciation

3. Reproductive Isolation
Is when some members of a population stop breeding with other members
Can be caused by physical, behavioral, or temporal barriers
Can cause speciation

4. Geographic Isolation
Occurs when a geographic barrier prevents contact and breeding between members of a population
Geographic barriers can include:
Bodies of water
Mountain ranges
Glaciers
Forests
Cities and roads
Can create reproductive isolation
When isolated groups come back into contact, they do not interbreed

6. Behavioral Isolation
Occurs when behaviors change and prevent contact and breeding between members of a population
Behavioral changes can include:
Food choices
Mating rituals
Can create reproductive isolation

7. Temporal Isolation
Occurs when members of a population mate at different times, which prevents contact
Can create reproductive isolation

8. How Darwin’s Finches Evolved
Founders Arrive
Birds fly or are blown 600 miles to Galapagos
Geographic Isolation
Birds are now separate from the mainland populations and other island populations
Changes in Gene Pools
Birds adapt to local environments, causing different beak sizes and other adaptations

9. How Darwin’s Finches Evolved
Behavioral Isolation
Different mating behaviors prevent breeding with other island populations
Competition
Competing for food and other resources causes further adaptations