Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
12. Explain how an island could support
large populations of both Large Ground
Finches and Small Ground Finches
The island would need to have both
large and small seeds available
b. How could you use the materials
provided in this lab to test your
explanation?
I would put many large and small seeds in separate dishes.
Then, I would run trials using tools from the “large-seed survivors” and tools
from the “small-seed survivors” to compete for the seeds in the dishes.
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
The diagram below shows variations in the beaks of finches in the Galapagos Islands.
1) The differences observed in the bird beaks in the given diagram are most likely due to
A) the genetic recombination associated with mitotic cell division
B) the genetic engineering of the DNA of each of these species
C) asexual reproduction of these finch species
D) the selection for different shaped beaks that best suit different niches
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
2) Small ground finches and medium ground finches live on an island with abundant plant and animal
food. Using the given diagram, predict how the small ground finch and the medium ground finch would
be affected if warbler finches migrated to the island where these finches live.
Small ground finch and Medium ground finch populations will slightly decreases,
because Warbler finches eats all animal food, whereas Small and medium ground finches eat
mostly plant food.
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
3) Which finch species is least likely to survive a severe drought that reduces the plant population
on the island? Support your answer with an explanation.
Large ground finch, because a bigger bird needs more food to survive.
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
4) Using information provided in the chart, identify two birds that would most likely compete for
food in times of food shortage and explain why they would compete.
Large ground finch and Medium ground finch, because they eat the same kinds of food.
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
The characteristics of four finches that inhabit the same island are represented in the chart below.
5) Complete the table below using information in the characteristics chart and your knowledge of
biology.
Large Ground
Finch
They eat different kinds of food
Small Ground
Finch
Warbler Finch
They eat same kinds of food
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
When Charles Darwin traveled to the Galapagos Islands, he observed 14 distinct varieties of
finches on the islands. Darwin also observed that each finch variety ate a different type of food
and lived in a slightly different habitat from the other finches. Darwin concluded that the
finches all shared a common ancestor, but had developed different beak structures.
6) The 14 varieties of finches mentioned in the reading passage are most likely the result of
A) lack of competition
B) asexual reproduction
C) biological evolution
D) absence of biodiversity
7) The different beak structures mentioned in the last sentence of the reading passage were most
likely influenced by
A) environmental conditions identical to those of the common ancestor
B) selection for favorable variations
C) characteristics that are acquired during the bird's lifetime
D) abnormal mitotic cell division
8) The second sentence in the reading passage best describes
A) a predator/prey relationship
B) a food web
C) a niche
D) an ecosystem
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
Average beak sizes of the seed-eating medium ground finch on one of the Galapagos Islands are shown in the
diagram below. During wet years, all types of seeds are abundant. The medium ground finch prefers to eat
small seeds that are easy to crush. However, during droughts (dry years), when small seeds are not as
abundant, they eat the larger seeds on the island.
9) How might an extended period of drought influence the ground finch population in the given situation?
A) The birds with smaller beaks would be more numerous.
B) Drought decreases seed availability, but has no influence on the ground finch.
C) Drought increases seed availability, and all ground finches would be more numerous.
D) The birds with larger beaks would be more numerous.
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
10) How would the introduction of another species of seed-eating ground finch to the island most likely
influence the medium ground finch in the given situation?
A) The finches would interbreed and produce a new species of finch.
B) The medium ground finch would face increased competition for seeds.
C) The medium ground finch would become a parasite of the introduced species.
D) The finches would not compete, since they both eat seeds.
11) Based on the information given, which factors most likely had a role in the development of beak
characteristics in the medium ground finch?
A) mutation and cloning
B) unchanging environment and the need to reproduce
C) genetic engineering and selective breeding
D) variation and recombination
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
12) The most likely explanation for the variation in the beak size of the medium ground finch shown in the
graph is that
A) different adaptations gave some birds a better chance for survival
B) the environment caused the birds to exercise their beaks and the beaks became longer and stronger
C) the birds acquired larger beaks so they could take advantage of the supply of small seeds
D) the birds with smaller beaks mutated due to the drought so they produced more offspring
13) Studies of the finches of the Galapagos Islands have shown that
A) natural selection occurs when there are scarce resources and intense competition
B) the beak of a finch will change if the environment of the bird remains stable
C) a bird's beak changes annually in response to the type of food that is most abundant each year
D) DNA will change to produce structures needed by birds to survive intense competition
Objective: Understand How Natural Selection Works through “The Beak of Finches” Lab
Key Words: Beak, adaptation, environment, survival of fit, differential reproduction
The diagram to the right shows four species of birds that evolved from an ancestral species that had a small,
pointed beak. Today, all four species inhabit the same island.
6) The four different types of beaks shown are most likely the result of
A) gene manipulation
B) patterns of behavior learned from parents
C) unchanging environmental conditions
D) natural selection
7) Which of the following statements best explains the variation in the beaks of these four species?
A) Competition for limited food resources led to selection for different traits.
B) Over time, an abundance of seeds for food led to increased differences between the species.
C) Over time, an abundance of seeds for food led to increased similarities between the species.
D) Competition for limited food resources led to selection for similar traits.
8) What factor most likely contributed to the evolution of Galapagos Islands finches with different beak
shapes?
A) similar climates on the different islands
B) cloning experiments carried out by native people on the islands
C) increased rate of asexual reproduction
D) competition between the finches for food