Module 3 Lesson 4 Practice Activity One
Gizmo Warm-up Darwin’s finches are one of many types of animals on the
Galápagos Islands that have unique adaptations, or traits that help anorganism
survive in its environment. The Rainfall and Bird Beaks Gizmo™allows you to
explore how rainfall influences the range of beak shapes found in a single finch
species.
1. The beak depth of a finch is the distance from the top of the beak to thebottom,
as shown.
A. What is the current average beak depth in the Gizmo?
9.86 mm
B. Select the HISTOGRAM tab. Do all the finches have the samebeak
depth? np
2. Click Play and let the simulation play for five years with average rainfall(10
inches/yr).
Select the GRAPH tab and view the Finches vs time and Beak depth vstime
graphs.
A. A. How does the finch population change? ? It changes over theyears,
but at the end of 5 years, it’s the same as it was at the start
B. Does the beak depth change significantly? no
Activity A: Normal years
Get the Gizmo ready: ∙ Click Reset
Introduction: The Galápagos Islands are very dry, with an average rainfall on
some islands of only five inches per year. The amount of rainfall has a large
impact on the abundance and types of seeds that are available to beeaten by
finches. In the process of natural selection, only the finches that are best adapted
to the available seed types survive and have offspring.
Question: How is the finch population affected by a period of averagerainfall?
Observe: With the Rain sliders set to 10 inches, click Play, and thenPause ( )
after one year has passed.
1. Select the TABLE tab and look at the Month and Finches columns.
, Module 3 Lesson 4 Practice Activity One
A. How did the finch population change over the course of one year?
? It changes over the years, but at the end of 5 years, it’s the same as it was at the
start
The finches have their young during the rainy season. Based on thetable,
which part of the year do you think is the rainy season?
A little before the halfway point. Spring time: April, May, June
Analyze: Click Reset, and choose the HISTOGRAM tab. The barsrepresent
the numbers of finches that have different beak depths.The range of beak
depths is equal to the difference between the largest and smallest beaks.
2. What is the average beak depth of the current finch population?
10.29
3. What is the range in beak depths in the population? 6 mm
4. Do most of the finches have beak depths near the lower extreme, the middle,
or the higher extreme of the range? the middle
5. Experiment: Click Play, and observe the histogram as the simulation
plays for five years.
6. What is the average beak depth now? _9.80
7. What is the current range of beak depths? 8mm_
Based on what you have seen, are finches with very small, medium, or very
large beaks most likely to survive in times of normal rainfall? Justify your
answer.
Small, because after the five years the average beak depth is 9.80mm, this isrelatively small
Activity B: Drought
Get the Gizmo ready: ∙ Click Reset.
Introduction: In years of extreme drought, Galápagos plants don’t produce
new seeds. The small, delicate seeds get eaten up quickly, leaving behind only
the largest, toughest seeds. Question: How doesdrought affect the finch
population and average beak depth?
Gizmo Warm-up Darwin’s finches are one of many types of animals on the
Galápagos Islands that have unique adaptations, or traits that help anorganism
survive in its environment. The Rainfall and Bird Beaks Gizmo™allows you to
explore how rainfall influences the range of beak shapes found in a single finch
species.
1. The beak depth of a finch is the distance from the top of the beak to thebottom,
as shown.
A. What is the current average beak depth in the Gizmo?
9.86 mm
B. Select the HISTOGRAM tab. Do all the finches have the samebeak
depth? np
2. Click Play and let the simulation play for five years with average rainfall(10
inches/yr).
Select the GRAPH tab and view the Finches vs time and Beak depth vstime
graphs.
A. A. How does the finch population change? ? It changes over theyears,
but at the end of 5 years, it’s the same as it was at the start
B. Does the beak depth change significantly? no
Activity A: Normal years
Get the Gizmo ready: ∙ Click Reset
Introduction: The Galápagos Islands are very dry, with an average rainfall on
some islands of only five inches per year. The amount of rainfall has a large
impact on the abundance and types of seeds that are available to beeaten by
finches. In the process of natural selection, only the finches that are best adapted
to the available seed types survive and have offspring.
Question: How is the finch population affected by a period of averagerainfall?
Observe: With the Rain sliders set to 10 inches, click Play, and thenPause ( )
after one year has passed.
1. Select the TABLE tab and look at the Month and Finches columns.
, Module 3 Lesson 4 Practice Activity One
A. How did the finch population change over the course of one year?
? It changes over the years, but at the end of 5 years, it’s the same as it was at the
start
The finches have their young during the rainy season. Based on thetable,
which part of the year do you think is the rainy season?
A little before the halfway point. Spring time: April, May, June
Analyze: Click Reset, and choose the HISTOGRAM tab. The barsrepresent
the numbers of finches that have different beak depths.The range of beak
depths is equal to the difference between the largest and smallest beaks.
2. What is the average beak depth of the current finch population?
10.29
3. What is the range in beak depths in the population? 6 mm
4. Do most of the finches have beak depths near the lower extreme, the middle,
or the higher extreme of the range? the middle
5. Experiment: Click Play, and observe the histogram as the simulation
plays for five years.
6. What is the average beak depth now? _9.80
7. What is the current range of beak depths? 8mm_
Based on what you have seen, are finches with very small, medium, or very
large beaks most likely to survive in times of normal rainfall? Justify your
answer.
Small, because after the five years the average beak depth is 9.80mm, this isrelatively small
Activity B: Drought
Get the Gizmo ready: ∙ Click Reset.
Introduction: In years of extreme drought, Galápagos plants don’t produce
new seeds. The small, delicate seeds get eaten up quickly, leaving behind only
the largest, toughest seeds. Question: How doesdrought affect the finch
population and average beak depth?
