1. Do now activity What is speciation?
Give an example of behavioral reproductive isolation. Explain.
Give an example of geographic reproductive isolation. Explain.
Give an example of temporal reproductive isolation. Explain.

2. Section 7-3: Gene frequency
Essential Question:
How do environmental factors impact gene (relative) frequency?
Learning Target
Justify why an advantageous trait will increase in proportion from one generation to another when provided statistical evidence.
Use data to explain how change in gene frequency caused by natural selection is related to environmental factors such as seasonal temperature, climate change, acidity, light, geographic barriers, & evolution of other organisms.
Section 7-3: Gene frequency

3. announcements Biology Tutoring this week:
Lunch B (Tuesday & Thursday)
7:00AM (Monday – Friday)
After school Biology Tutoring: Tuesday
Section 6 Quiz Retakes are available until 2/17/17.

4. announcements Available Extra Credit: Tissue Box = 2 Points
Starburst Original Jellybeans = 5 Points
Stauffer’s Original Animal Crackers = 10 Points

5. Don’t forget to chunk your notes!

6. ____ _____ is the number of times an allele occurs in a gene pool.
overview
____ _____ is the number of times an allele occurs in a gene pool.
Gene/Relative Frequency
Evolution (genetic terms): any change in the relative frequency of alleles in a population

7. overview
Relative (gene) frequency is the number of times an allele occurs in a gene pool.
Gene/Relative Frequency
Evolution (genetic terms): any change in the relative frequency of alleles in a population

8. overview
Genetic drift is a random change in relative frequency because of chance.

9. In small populations, there can be more or less of an allele just by chance.
Examples:
Natural disasters
Alleles passed on are random
overview
Remember, the smaller the group the less likely it will reflect the laws of probability
Ex: coin toss

10. In small populations, there can be more or less of an allele just by chance.
Examples:
Natural disasters
Alleles passed on are random
overview
Remember, the smaller the group the less likely it will reflect the laws of probability
Ex: coin toss

11. In small populations, there can be more or less of an allele just by chance.
Examples:
Natural disasters
Alleles passed on are random
overview
Remember, the smaller the group the less likely it will reflect the laws of probability
Ex: coin toss

12. Natural selection ICE AGE
Directional Selection can be caused when nature is against one end of variation.
ICE AGE

13. Natural selection DROUGHT
Stabilizing Selection can be caused when nature is against both ends of variation.
DROUGHT

14. Disruptive Selection can be caused when nature is against the most common variation.
Natural selection
FUR COAT INDUSTRY

15. Founder effect
Founder effect is when relative frequencies change because a small group of the population moves away.
cyclins

16. Founder effect
Founder effect is when relative frequencies change because a small group of the population moves away.
cyclins

17. Founder effect
If, by chance, an individual with a specific allele can reproduce a lot, then there will be more of the allele in the population.
cyclins

18. Sample of Original Population
examples
Sample of Original Population

19. Sample of Original Population
examples
Founding Population A
Sample of Original Population
Founding Population B

20. Sample of Original Population
examples
Founding Population A
Sample of Original Population
Descendants
Founding Population B

21. Do now activity How is the picture an example of genetic drift?
How is the picture an example of Founders Effect?
Genetic drift because the relative frequency changed from mutation at 4.5% to 20% to 41% (Total is 22) because of earthquake/death/etc.
Founders because Small group moved away so relative frequency of original population went from 4.5% to 0% mutation