1. March 23, 2017
Objective: Analyze and evaluate how natural selection produces change in populations, not individuals (TEKS 7C)
WE WILL:
Complete Isolation Notes
YOU WILL:
Isolation Activity

2. The Process of Speciation
Isolation Notes

3. Vocabulary- Words to Know!
Species – interbreeding populations of organisms that can produce fertile offspring
Speciation – formation of a new species

4. Reproductive Isolation
Reproductive Isolation – when members of two populations cannot interbreed and produce fertile offspring
Horses and donkeys can mate and produce a mule. However, all mules are infertile females.

5. How do organisms become isolated?
Behavioral isolation – when 2 populations are capable of interbreeding but have differences in courtship rituals or other reproductive strategies that involve behavior
Blue footed boobies

6. How do organisms become isolated? (cont.)
2. Geographic isolation – when 2 populations are
separated by geographic barriers such as rivers, mountains or bodies of water

7. How do organisms become isolated? (cont.)
3. Temporal Isolation- when 2 or more species reproduce at different times
Different seasons or different times of the day.
Example: 3 similar species of orchids live in the same rain forest. Each species has flowers that last only one day and must be pollinated (reproduce) on that day to produce seeds. Because the species bloom at different times of the year they cannot pollinate one another.

8. Speciation in Darwin’s Finches
Darwin found over a dozen different species of finches on the Galapagos Islands that all evolved from a common ancestor
How?
Speciation in Galapagos finches by founding of a new population
Geographical isolation
Changes in the new populations gene pool
Behavioral isolation and ecological competition
Pg 496

9. PARTNER QUESTIONS What is Geographical Isolation?
A newly formed lake divides a population of a beetle species into two groups. What other factors besides isolation might lead to the two groups becoming separate species?