Student Exploration: Microevolution
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. What is fitness?
The ability to survive and reproduce
2. What is an allele?
A form of a gene or a gene variant.
3. How might a population’s gene pool help increase its fitness in an environment?
A certain gene may be very good for its survival which will cause that organism to
reproduce and have a better chance at survival.
Gizmo Warm-up
m
er as
If natural selection does not favor one trait over
co
another, the frequencies of various alleles in a
eH w
population will tend to be stable over long periods of
o.
time. But what happens when one allele confers an
rs e
advantage or disadvantage to an individual? These
ou urc
scenarios and others can be explored with the
Microevolution Gizmo™.
o
1. The feather color of the parrots in the Gizmo is
aC s
vi y re
controlled by two alleles, D and d. The D allele is incompletely dominant over d. What
is the feather color of each parrot genotype?
DD = dark green Dd = light green dd= yellow
ed d
ar stu
2. The fitness of parrots is determined by how well they blend into the background
trees. Set the Fitness of DD slider to 100% and the other fitness sliders to 60%.
is
Th
The birds with which genotype blend into the background now? DD
3. Click Begin, and then click Predator. Which parrots were killed by predators?
_Yellow and light green _________
sh
Why?
Their feathers do not blend into the background making them targets.
This study source was downloaded by 100000828326221 from CourseHero.com on 08-14-2021 03:12:00 GMT -05:00
https://www.coursehero.com/file/30508290/Microevolution-Gizmodocx/
, Activity A: Get the Gizmo ready:
Deleterious · Click Reset.
dominant · Set the DD and dd sliders to 34%.
alleles
Introduction: A deleterious allele is one that significantly lowers the fitness of an
individual. If the deleterious allele is a dominant allele (D), then both homozygous
DD and heterozygous Dd individuals will be at a disadvantage.
Question: How will allele frequencies change if a dominant allele is
deleterious?
1. Observe: To model the effects of a deleterious dominant allele, set the Fitness of
DD and Fitness of Dd sliders to 60%. Set the Fitness of dd to 100%.
Based on the color of the trees, which parrots will be easiest for predators to spot and
kill?
m
er as
co
The dark green colored parrots.
eH w
o.
2. Predict: How do you expect the proportions of D and d alleles to change in five
generations? rs e
ou urc
It will become more common for dd to be the chosen allele for the birds because of the
adaptation to their surroundings.
o
aC s
3. Record: Click Begin and Predator. Record the results of hawk predation in the
vi y re
table below.
ed d
DD Dd dd Totals
ar stu
Starting population 240 20 240 500
is
Killed by hawks 87 10 1 98
Th
Ending population 153 10 239 402
4. Calculate: To calculate the percentage of survivors for each genotype, divide the
sh
Ending population by the Starting population. Multiply each result by 100 to
convert to a percentage, and record the percentages below.
DD 63.75% Dd 50% dd 99.58 %
5. Analyze: How do the percentages of survivors relate to the fitness of each parrot
genotype?
This study source was downloaded by 100000828326221 from CourseHero.com on 08-14-2021 03:12:00 GMT -05:00
https://www.coursehero.com/file/30508290/Microevolution-Gizmodocx/
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. What is fitness?
The ability to survive and reproduce
2. What is an allele?
A form of a gene or a gene variant.
3. How might a population’s gene pool help increase its fitness in an environment?
A certain gene may be very good for its survival which will cause that organism to
reproduce and have a better chance at survival.
Gizmo Warm-up
m
er as
If natural selection does not favor one trait over
co
another, the frequencies of various alleles in a
eH w
population will tend to be stable over long periods of
o.
time. But what happens when one allele confers an
rs e
advantage or disadvantage to an individual? These
ou urc
scenarios and others can be explored with the
Microevolution Gizmo™.
o
1. The feather color of the parrots in the Gizmo is
aC s
vi y re
controlled by two alleles, D and d. The D allele is incompletely dominant over d. What
is the feather color of each parrot genotype?
DD = dark green Dd = light green dd= yellow
ed d
ar stu
2. The fitness of parrots is determined by how well they blend into the background
trees. Set the Fitness of DD slider to 100% and the other fitness sliders to 60%.
is
Th
The birds with which genotype blend into the background now? DD
3. Click Begin, and then click Predator. Which parrots were killed by predators?
_Yellow and light green _________
sh
Why?
Their feathers do not blend into the background making them targets.
This study source was downloaded by 100000828326221 from CourseHero.com on 08-14-2021 03:12:00 GMT -05:00
https://www.coursehero.com/file/30508290/Microevolution-Gizmodocx/
, Activity A: Get the Gizmo ready:
Deleterious · Click Reset.
dominant · Set the DD and dd sliders to 34%.
alleles
Introduction: A deleterious allele is one that significantly lowers the fitness of an
individual. If the deleterious allele is a dominant allele (D), then both homozygous
DD and heterozygous Dd individuals will be at a disadvantage.
Question: How will allele frequencies change if a dominant allele is
deleterious?
1. Observe: To model the effects of a deleterious dominant allele, set the Fitness of
DD and Fitness of Dd sliders to 60%. Set the Fitness of dd to 100%.
Based on the color of the trees, which parrots will be easiest for predators to spot and
kill?
m
er as
co
The dark green colored parrots.
eH w
o.
2. Predict: How do you expect the proportions of D and d alleles to change in five
generations? rs e
ou urc
It will become more common for dd to be the chosen allele for the birds because of the
adaptation to their surroundings.
o
aC s
3. Record: Click Begin and Predator. Record the results of hawk predation in the
vi y re
table below.
ed d
DD Dd dd Totals
ar stu
Starting population 240 20 240 500
is
Killed by hawks 87 10 1 98
Th
Ending population 153 10 239 402
4. Calculate: To calculate the percentage of survivors for each genotype, divide the
sh
Ending population by the Starting population. Multiply each result by 100 to
convert to a percentage, and record the percentages below.
DD 63.75% Dd 50% dd 99.58 %
5. Analyze: How do the percentages of survivors relate to the fitness of each parrot
genotype?
This study source was downloaded by 100000828326221 from CourseHero.com on 08-14-2021 03:12:00 GMT -05:00
https://www.coursehero.com/file/30508290/Microevolution-Gizmodocx/
