Evolution of Populations AP Biology Chapter 23 Evolution of Populations

Variation Exists

Variation Exists

Variation in Crossover

Variation in Anaphase I

Variation in Anaphase II

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

Genetic Drift “Random change”

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

Genetic Drift – Bottleneck effect Original population Bottlenecking event Surviving population

“Founding fathers”

“Founding fathers”

“Founding fathers”

Gene Flow (Movement on purpose)

Gene Flow (Movement on purpose)