Download Shifts in Allele Frequencies

Honors Biology
Unit: Evolution
Shifts in Phenotypic Frequencies
Procedures:
1. Each group needs to begin with eight beads of each color.
2. Mating rules:
a. Green is dominant to all.
b. Blue is dominant to all except green.
c. Yellow is recessive to all.
d. Red is recessive to all except yellow.
3. After each mechanism occurs, the following occurs each generation.
a. Eight pairs of individuals randomly mate.
b. Then, ten percent of each generation die, randomly.
4. You will proceed through the third generation for each mechanism.
Mechanism: Genetic Drift: a great  in pop’n size in a generation. All Yellow, Red, & ½ Blue
survive a deadly viral infection! All Green are killed!
Generation
1
Yellow
Beads
Red
Beads
Blue
Beads
Green
Beads
Total # of
individuals
8
8
8
8
32
1 After Mechanism
1 After Mating
1 After Mortality
2 After Mating
2 After Mortality
3 After Mating
3 After Mortality
Mechanism: Gene Flow: all Blue individuals emigrate. Four Green immigrate.
kmz
Metro HS
Honors Biology
Generation
1
Unit: Evolution
Yellow
Beads
Red
Beads
Blue
Beads
Green
Beads
Total # of
individuals
8
8
8
8
32
1 After Mechanism
1 After Mating
1 After Mortality
2 After Mating
2 After Mortality
3 After Mating
3 After Mortality
Mechanism: Natural Selection: due to climate change, Yellow individuals are selected for! Their
Yellow coat helps these organisms now hide from predators!
Generation
1
Yellow
Beads
Red
Beads
Blue
Beads
Green
Beads
Total # of
individuals
8
8
8
8
32
1 After Mechanism
1 After Mating
1 After Mortality
2 After Mating
2 After Mortality
kmz
Metro HS
Honors Biology
Unit: Evolution
3 After Mating
3 After Mortality
Mechanism: Mutation: Orange allele forms! Dominant to all other genotypes! A new pathway
to produce ATP! Mate Gen 1, then 20% randomly become ORANGE!
Generation
1
Orange
Beads
Yellow
Beads
Red
Beads
Blue
Beads
Green
Beads
Total # of
individuals
8
8
8
8
32
1 After Mechanism
1 After Mating
1 After Mortality
2 After Mating
2 After Mortality
3 After Mating
3 After Mortality
kmz
Metro HS
Honors Biology
Unit: Evolution
Mechanism: Sexual Selection: Red phenotypes sought ought by mating females! If their 1st or 2nd
random mate is not red, then they try one more time to have a red partner!
Generation
1
Yellow
Beads
Red
Beads
Blue
Beads
Green
Beads
Total # of
individuals
8
8
8
8
32
1 After Mechanism
1 After Mating
1 After Mortality
2 After Mating
2 After Mortality
3 After Mating
3 After Mortality
kmz
Metro HS