1. Evolution of Populations
AP Biology Chapter 23
Evolution of Populations

2. Variation Exists

3. Variation Exists

4. Variation in Crossover

5. Variation in Anaphase I

6. Variation in Anaphase II

7. Variation in Egg and sperm (Which sperm will it be?)

8. Genetic Drift “Random change”

9. Evolution of Allele frequency
CRCR
CRCR
CWCW
CRCR
CRCR
CRCW
Only 5 of
10 plants
leave
offspring
CRCW
Only 2 of
10 plants
leave
offspring
CRCR
CRCR
CWCW
CRCR
CRCR
CWCW
CRCR
CRCR
CRCW
CRCW
CRCR
CRCR
CRCR
CRCW
CWCW
CRCR
CRCR
CRCR
CRCW
CRCW
CRCW
CRCR
CRCR
Generation 1
p (frequency of CR) = 0.7
q (frequency of CW) = 0.3
Generation 2
p = 0.5
q = 0.5
Generation 3
p = 1.0
q = 0.0

10. Genetic Drift – Bottleneck effect
Original
population
Bottlenecking
event
Surviving
population

11. “Founding fathers”

12. “Founding fathers”

13. “Founding fathers”

14. Gene Flow (Movement on purpose)

15. Gene Flow (Movement on purpose)