Embedded Files
Objectives
Objectives
Quiz 1:
Describe the “ingredients” of natural selection.
List the sources of genetic variation.
Explain changes in allele frequency as the outcome of differential reproduction - natural selection.
Analyze and make predictions about natural selection scenarios.
Differentiate between stabilizing, directional, disruptive selection.
Define sexual selection.
Distinguish between change due to selection and change due to genetic drift.
Identify the types of populations most significantly affected by genetic drift.
Distinguish between the two kinds of genetic drift.
Explain how their rapid rate of reproduction affects the rate at which viruses and bacteria are able to evolve and adapt relative to eukaryotic organisms.
Quiz 2:
Be able to calculate allele frequencies given the number of homozygous. dominant, heterozygous, and homozygous recessive individuals in a population
List the five conditions for a population to be at Hardy-Weinberg Equilibrium.
Analyze and make predictions about speciation scenarios.
Describe the role that isolation/barriers play in speciation.
List examples of different lines of evidence that can be used to investigate evolutionary history.
Analyze evidence from comparative anatomy (homology and embryology), the fossil record, DNA, and biogeography to determine common ancestry.
Distinguish between homologous and analogous structures.
Distinguish between artificial selection and natural selection.
Distinguish between convergent and divergent evolution.
Be able to make and interpret a cladogram (identify last common ancestors, rank relatedness of sister taxa, and determine inheritance of shared derived characteristics).
Vocabulary
Vocabulary
Quiz 1:
Adaptation
Allele frequency
Bacteria
Bottleneck effect
Common ancestor
Charles Darwin
Differential reproductive success
Directional Selection
Disruptive Selection
Eukaryote
Evolution
Extinction
Fitness
Founder effect
Gene pool
Genetic drift
Lamarck / Acquired Characteristics
Natural selection
Phenotype frequency
Prokaryote
Sexual selection
Stabilizing Selection
Variation
Virus
Quiz 2:
Analogous structure
Artificial selection
Barrier to gene flow
Behavioral isolation
Cladogram
Convergent evolution
Derived characteristic
Divergent evolution
Embryology
Endosymbiosis
Fossil/Fossil record
Frequency (as in Allele Frequency)
Geographic isolation
Gene flow
Hardy-Weinberg Equilibrium
Homologous structure
Homology
Industrial melanism
Last or most recent common ancestor
Phylogenetic tree
Postzygotic isolation
Prezygotic isolation
Reproductive isolation
Sister taxa
Speciation
Species
Taxon/Taxa
Temporal isolation
Transitional form
Vestigial structure
Textbook Reference
Textbook Reference
Quiz 1:
7.2: Unequal reproductive success leads to natural selection
7.3: Evolution affects our daily lives
7.6: Populations are units of evolution
7.7: Evolution proceeds through several mechanisms
Quiz 2:
7.4: The fossil record provides important evidence for evolution
7.5: Evidence for evolution is found in the natural world
7.8: The geologic record ties together the history of Earth and its life
7.9: Macroevolution encompasses large-scale changes
7.10: Species are maintained by reproductive barriers
7.11: Speciation can occur through various mechanisms
7.13: Phylogenetic trees represent hypotheses about evolutionary history
Relevant Files
Relevant Files
Sample MCAS Questions
Sample MCAS Questions
Quiz 1:
1. Dutch elm disease is a fungal infection of elm trees that usually results in death. The disease has killed millions of North American elm trees that were not resistant to the fungus. Scientists have bred resistant elms by crossing North American species with Asian species that show resistance.
Which of the following best describes how natural selection would promote resistant elm populations once the resistance genes from the Asian species were successfully introduced?
A. After encountering elms with resistance genes, fungi would avoid elms and begin to attack other tree species.
B. Resistance would spread to all of the mature elms in a population from the few trees that acquired resistance.
C. By reproducing with each other, elm trees with resistance genes would create super-resistant elms with twice the number of resistance genes.
D. Elm trees with resistance genes would survive and pass on resistance to offspring, while trees without resistance would more likely be killed by the fungus.
2. The outermost tail feather of the male barn swallow is longer than that of the female barn swallow. The long tail feather helps the males attract females, but it also requires the males to use extra energy to fly.
The long tail feather trait is maintained in the barn swallow populations because, compared to males with a shorter tail feather, males with a longer tail feather are more likely to
A. build a large nest.
B. produce offspring.
C. migrate each winter.
D. escape from predators.
3. The graph below relates the number of grey squirrels in a population to their coat color.
This squirrel population has been separated from other squirrel populations by a new highway and several construction sites. The main predators of these squirrels are cats and hawks.
a. Assume that dark gray squirrels are very visible in this new environment. What is likely to happen to the distribution of coat color in this squirrel population over several generations? Sketch a graph to show the predicted distribution, and explain your answer.
b. Assume that dark gray squirrels are very visible on the ground, and light gray squirrels are very visible in the trees. Explain what is likely to happen to the distribution of coat color in the squirrel population over several generations. You may sketch a graph in your Student Answer Booklet as part of your explanation.
4. Starting in 1954, commercial fishers in the northwest Pacific were paid by weight, rather than by the individual fish, for pink salmon. The fishers increased the use of a type of net that selectively catches larger fish.
Which of the following effects did this change in fishing techniques most likely have on the salmon population over the next 20 years?
A. The average body size of the salmon increased significantly.
B. The average body size of the salmon decreased significantly.
C. The average body size of the males in the salmon population increased and the average body size of females in the salmon population stayed the same.
D. The average body size of the males in the salmon population stayed the same and the average body size of the females in the salmon population increased.
5. European rabbits were introduced to Australia in 1859. The rabbits reproduced rapidly in their new habitat, displaced other animals, and overgrazed vegetation. In an attempt to reduce the rabbit population, a virus was introduced in 1951. This virus is usually deadly to European rabbits.
When the virus was first introduced, the rabbits died in large numbers, but the death rate decreased over time. Which of the following best explains the decrease in the rabbit death rate?
A. Young rabbits learned to avoid being infected with this virus.
B. Natural selection favored rabbits that are resistant to this virus.
C. The lifespan of this virus is too short to affect rabbits over a long period of time.
D. The rabbits that were originally infected with this virus have been dead for many years.
6. In a mouse population inhabiting a grassland area, a mutation occurs that results in a new coat color allele.
Which of the following factors has the greatest effect on whether the new coat color will become more common in the mouse population?
A. Whether abundant food is available in the grassland.
B. Whether the new coat color allele is dominant or recessive.
C. Whether the rate of reproduction in the mouse population is stable.
D. Whether the new coat color allele increases the survival of mice in their environment.
7. Some willow trees alter the chemical composition of their leaves when attacked by caterpillars. Compared to normal leaves, the chemically altered leaves are less nutritious and are more difficult for caterpillars to digest.
Which of the following is a likely effect of this ability to alter leaf composition?
A. Willow trees with this ability will attract more caterpillars than other willow trees.
B. Willow trees with this ability will have a survival advantage over other willow trees.
C. More butterflies will lay their eggs on willow trees with this ability than on other willow trees.
D. Caterpillars that feed on willow trees with this ability will be larger than caterpillars on other willow trees.
8. The illustration below shows several wild canine species that descended from a common canine ancestor.
As a result of natural selection, canine biodiversity increased a all of these species developed from a common ancestor. Which of the following factors contributed most to the evolution of these diverse canine species?
A) Differences in environment
B) Selective breeding programs
C) Inheritance of learned behaviors
D) Interbreeding with unrelated species
9. The illustration below shows two snakes of the same species that have different striping.
California king snakes may exhibit different patterns of stripes. According to evolution by natural selection, which of the following is the most likely result if a snake-eating predator can more easily detect the snakes with the crosswise stripes?
A) The percentages of snakes born of each type will not change
B) Snakes with lengthwise stripes will become more common
C) Snakes with crosswise stripes will learn to move faster
D) A new type of king snake with no stripes will emerge
10. Here is a statement about mutations:
"In many cases throughout geologic history, if mutations in the genetic material of existing species had not occurred, new species would not have appeared."
Which of the following conclusions about mutations in the DNA sequence of a gene is most consistent with the statement?
A) Mutations are always rapidly occurring.
B) Mutations are always beneficial.
C) Mutations are the only way new species arise.
D) Mutations are an important mechanism for the evolution of new species.
11. The graph below represents the range of birth weights for offspring in a mammal population. As is typical in many mammal populations, offspring with an average weight at birth have a higher survival rate than offspring with a very low or very high birth weight. Based on this information, which of the following graphs is the best prediction of what will happen to the range of birth weights in this population over time?
12. Major natural events, such as volcanic eruptions, significantly change the environmental conditions of the areas where events occur. What happens to local populations that are unable to adapt to the new conditions or to move to other areas?
A) They become extinct.
B) They undergo rapid mutations.
C) They develop a scavenger lifestyle until conditions change.
D) They interbreed with the populations of other species that have remained there.
13. The table below shows data from an insect population in 1995 and 1998. Insecticides were applied to this population from the year 1995 to 1998.
CHANGES IN AN INSECT POPULATION'S RESISTANCE TO INSECTICIDE
Characteristic
Percent in Population in 1995
Percent in Population in 1998
resistant
0.15
99.10
not resistant
99.85
0.90
a) Based on the data in the table, describe the changes in the characteristics of the insect population between 1995 and 1998.
b) Explain, in detail, how natural selection produced these changes in the insect population over this time.
14. The rock pipit and the water pipit are two types of birds found in the United Kingdom and other areas of Europe. The rock pipit and the water pipit have similar appearances and their habitat ranges overlap.
Which of the following observations most likely caused scientists to classify the birds as separate species?
A. The rock pipit is not able to produce fertile offspring with the water pipit.
B. The rock pipit population in the United Kingdom is larger than the water pipit population.
C. The rock pipit eats insects, fish, and seeds, but the water pipit eats only insects and larvae.
D. The rock pipit remains in the United Kingdom year round, but the water pipit only overwinters there.
15. A mutation in an allele in an individual newt gave that newt faster reflexes. It is found that, after many generations, most of the newt population has the new allele. Which of the following most likely caused this change?
A. The newt gave its mutated allele to other adult newts.
B. Other newts learned to copy the strategies of the mutated newt.
C. The same mutation occurred in other newts as a result of environmental conditions.
D. Newts with the mutation are better able to survive and reproduce than newts without the mutation.
16. Some male guppies show variation in their scale pattern. Male guppies can have a dull color that blends with the sand on streambeds, or they can have large spots that are highly visible.
A researcher is studying a sandy portion of a particular stream where most of the male guppies have large spots. A predatory fish invades the area. The predatory fish find the guppies primarily by sight. Over time, which of the following is the most likely effect of the predators on the male guppies' scale pattern?
A. Most of the males will have large spots.
B. Most of the males will have a dull color.
C. Half of the males will have spots and half of the males will be dull.
D. Half of the males will have even larger spots and half of the males will have even smaller spots.
17. Which of the following examples best illustrates the process of evolution by natural selection?
A. A person with asthma has trouble breathing.
B. A group of species has common DNA sequences.
C. A man and a woman have 10 children together.
D. A population becomes immune to a lethal disease over many generations.
18. The diagrams below show changes in a desert lizard population.
Which biological concept is illustrated?
A. Polygenic traits
B. Natural selection
C. Sex-linked inheritance
D. Silent mutations
19. About 70 years ago, cane toads were introduced to Australia. The toads are toxic to some species of snakes, such as Dendrelaphis punctulatus. The longer an individual snake is, the greater its chance of survival after eating a cane toad. Which of the following did scientists most likely observe in the D. punctulatus snake population as a result of the presence of the cane toads?
A. The entire population was killed by the toads.
B. The entire population became resistant to the toads.
C. The average body length in the population increased.
D. The average body length in the population decreased.
Quiz 2:
20. Which of the following provides the most conclusive evidence that organisms of two different species share a common ancestor?
A. They live in the same ecosystem.
B. They reproduce at the same time.
C. They have similar DNA sequences.
D. They have similar body movements.
21. Which of the following best explains how the fossil record provides evidence that evolution has occurred?
A. It indicates that forms of life existed on Earth at least 3.5 billion years ago.
B. It indicates the exact cause of structural and behavioral adaptations of organisms.
C. It shows how the embryos of many different vertebrate species are very similar.
D. It shows that the form and structure of groups of organisms have changed over time.
22. On island chains like the one shown below, animal populations that spread from the main island to the other islands can evolve into separate species.
Which of the following best explains what favors speciation in this situation?
A. Predators on the main island can easily migrate to follow the populations to the other islands.
B. Lack of disease on the other islands enables the populations to grow and change without limit.
C. The physical separation of the islands limits gene flow and interbreeding between the populations.
D. The climatic conditions of the islands allow the populations to breed all year and produce several generations.
23. Frogs, lizards, and birds all have a similar arrangement of bones in their limbs. Which of the following does this similarity most likely indicate about these animals?
A. They move in the same way.
B. They have a common ancestry.
C. They evolved at the same time.
D. They are comparable in size as adults.
24. On the Galápagos Islands, finches adapted over time to different food sources through changes in their beak structure.
Which of the following most likely resulted from the finches’ beak structure adaptations?
A. A decreased predation on finches.
B. An increased species diversity of finches.
C. An increased competition among finches.
D. A decreased reproductive rate in finches.
25. Caytonia is an extinct plant that existed between 200 and 140 million years ago. It had reproductive structures that resemble structures in modern flowering plants.
How do scientists know about the structures of this ancient extinct plant?
A. Scientists study the DNA sequences of Caytonia.
B. Scientists genetically engineer modern plants to produce Caytonia.
C. Scientists excavate and examine the fossilized remains of Caytonia.
D. Scientists observe the adaptations of plants in habitats resembling those of Caytonia.
26. The illustrations below show a South American finch and some of the species of finches found on the Galápagos Islands. The map shows the relationship of the Galápagos Islands to the west coast of South America.
There are 13 species of finches found on the Galápagos Islands. These finches have a wide variety of food sources and beak shapes. There is one genetically similar species of finch found on the South American mainland. This finch eats small seeds.
Use the map and the bird illustrations to identify and explain two ways that these finches provide evidence that supports the theory of evolution.
27. Similar structures are present in the embryos of fish, chickens, and rabbits. In fish, these structures develop into gills, but in chickens and rabbits, they either disappear or develop into other body parts later in embryonic development.
Which of the statements below best explains the presence of these structures in the embryos of all three species?
A. The embryos of the three species are similar in size.
B. Breathing structures are similar among the young of the three species.
C. The three species have a common ancestor with these embryonic structures.
D. The reproductive mechanisms are similar among the adults of the three species.
28. The illustrations below show vestigial pelvic bones of a baleen whale and vestigial hind limb bones of an extinct whale.
The presence of these bones in the baleen whale and the extinct whale provides evidence of which of the following?
A. Whales can travel on land when necessary.
B. Whales evolved from four-legged animals.
C. Whales have functional legs that are hidden by fat and skin.
D. Whales are developing into animals with four functioning limbs.
29. The drawings show some trilobite and crinoid fossils.
Which of the following is the most reasonable conclusion when fossils of these two different types of organisms are found in the same layers of rock?
A. Crinoids were prey of trilobites.
B. Crinoids were ancestors of trilobites.
C. Crinoids and trilobites had similar ancestors.
D. Crinoids and trilobites lived at the same time.
30. Some scientists use molecular evidence to study evolution. One type of molecular evidence is the amino acid sequence of particular proteins in various species.
Which of the following best describes what the study of these sequences reveals about the species?
A) The more similar sequences are, the faster the species will coevolve
B) The more similar the sequences are, the more closely related the species are
C) The longer the sequences are, the earlier the species evolved in geologic history
D) The longer the sequences are, the more adapted the species are to their environments
31. In 1861, a complete skeleton of an Archaeopteryx was discovered in limestone rocks that were 150 million years old. The fossils showed that this Archaeopteryx had a long bony tail, three claws on each wing, and a mouth full of teeth - which are all characteristics of dinosaurs - but it also had feathers on the long bony tail.
The fossil evidence supports an evolutionary link between which two animal groups?
A) Fishes and birds
B) Reptiles and birds
C) Mammals and reptiles
D) Amphibians and fishes
32. The bone structures of a porpoise flipper and a bat wing are shown below.
Which of the following conclusions is best supported by the structure of each limb?
A) The porpoise and bat share a common ancestor.
B) The porpoise and bat limbs are adapted primarily for grasping.
C) The porpoise and bat evolved relatively recently in geologic history.
D) The porpoise and bat limbs are designed to support the entire weight of the animal.
33. Scientists believe that the first organisms that appeared on Earth were prokaryotic. Which of the following best represents what the cell structure of these organisms may have looked like? Images are presented in the order A, B, C, D.
(Questions 34-36)
Madagascar is an island located off the east coast of Africa, as shown on the map below.
Madagascar has a unique animal community. Lemurs are one of the animal groups that have diversified extensively on Madagascar. Lemurs are primates, which is an order of mammals that also includes monkeys and apes. Lemur species vary widely in habitat, diet, size, and color. Lemurs only live on the island of Madagascar. However, fossil evidence shows that lemur ancestors existed on Africa's mainland. Scientists hypothesize that lemur ancestors reached Madagascar by floating across the Mozambique Channel on matted clumps of vegetation.
Four different lemur species are shown in figures 1-4 below.
Figure 1, Mouse lemur. Length: 12.5 cm. Habitat: Rain forest and deciduous forest.
Figure 2, Verreaux's sifaka. Length: 45 cm-55 cm. Habitat: Spiny deciduous forest and evergreen forest.
Figure 3, Ring-tailed lemur. Length: 38 cm-46 cm. Habitat: Deciduous forest and scrub forest.
Figure 4, Red-bellied lemur. Length: 36 cm-54 cm. Habitat: Rain forest
34. Lemur body types can vary widely. In addition to fossils and comparative anatomy, which of the following types of evidence can scientists reliably use to study the evolution of the variety of lemur body types?
A. lifespan
B. population sizes
C. DNA sequences
D. male-to-female ratio
35. There are at least 88 species of lemurs in existence today. Which of the following conditions most likely existed and made it possible for Madagascar's original lemur ancestors to evolve into many species on the island?
A. presence of a deadly virus that infected only lemurs
B. complete isolation from other small mammal species
C. new niches to adapt to in the absence of a large number of competitors
D. climatic conditions that were very different from those in mainland Africa
36. The lemurs shown in figures 1-4 all have prominent body features, such as eyes, fingers, legs, tails, and coats.
a. Choose three of the lemurs in the figures.
b. Using the figures, identify one prominent, visual feature for each of the lemur species you chose. Then describe a likely scenario in which natural selection favored the evolution of this feature. Be sure to discuss a different feature for each lemur.
37. Scientists have concluded that snakes evolved from an ancestor with legs. Which of the following statements provides the best evidence for this conclusion?
A. Most species of snakes live on land.
B. Snakes move extremely fast to catch their prey.
C. Snakes have a well-developed backbone and muscular system.
D. Some species of snakes have limb buds during their embryonic development.
38. Evolution can be seen in the fossil record in which of the following ways?
A. Organisms in the fossil record are identical to living organisms.
B. Individual species disappear and reappear in the fossil record.
C. The fossil record provides evidence that organisms have changed over time.
D. The fossil record provides evidence that all organisms developed at the same time.
39. Danaus plexippus and Danaus gilappus are two species of butterflies. Which of the following statements best explains why scientists classify them as two different species?
A. Only one of the species migrates in winter.
B. Only one of the species is found in North America.
C. The two species are not eaten by the same predators.
D. The two species cannot produce fertile offspring with each other.
40. Scientists believe that three species of lizards living on the Canary Islands descended from the same ancestor. Similarities in which of the following would most strongly support the scientists' hypothesis?
A. body size
B. main diet
C. population sizes
D. amino acid sequences
41. There are about 136 species of fireflies. Each species produces a different pattern of flashing light. Which of the following statements best explains how the different light signals help maintain separate firefly species?
A. The light signals are only flashed during mating season.
B. A male responds only to the light signals of females of his own species.
C. The light signals change in pulse duration or frequency every few years.
D. A male uses his light signal to repel all other males of the same and other species.
42. According to plate tectonic theory, Australia was part of the supercontinent Pangea. Millions of years ago Pangea divided, and eventually Australia was separated as its own continent. Which of the following is most likely a result of the isolation of the Australian continent for millions of years?
A. Australia has no fossil record of species evolution.
B. Australia has a large number of species that are not found anywhere else.
C. Plant populations in Australia have all evolved to be self-pollinating to maximize their chance for reproduction.
D. Animal populations in Australia have little genetic diversity and are less likely to survive environmental change.
43. Cacti in the Sonoran desert in North America share many characteristics with Euphorbia in the Sahara Desert in Africa.
Both types of plants have reduced leaves, prickly spines, and fleshy stems that contain water. Cacti and Euphorbia, however, are not closely related plants.
a. Describe how scientists used molecular evidence to determine that cacti and Euphorbia are not closely related plants.
b. Usually organisms that share many physical characteristics are closely related. Explain why cacti and Euphorbia evolved similar features.
c. Choose two similar characteristics of cacti and Euphorbia. Describe how each characteristic benefits the plants in their environments.
44. A student researching bears found the chart below in a textbook. The chart shows the classifications of several types of bears.
Which of the following conclusions is best supported by the data given in this chart?
A. Modern bears evolved from species that are now extinct.
B. The short-faced bear was the ancestor of the Asiatic black bear.
C. Present day bear species are more closely related than their ancestors were.
D. Natural selection favored the brown bear over the American black bear.
45. Along the Pacific coast of North America, there are at least seven subspecies of Ensatina eschscholtzii salamanders. All of them descended from a common ancestral population. As the species spread, subpopulations adapted to their local environments.
Which of the following must have increased as a result of these adaptations?
A. the number of chromosomes in each salamander
B. the size of each salamander in the population
C. the biodiversity of the total salamander population
D. the number of offspring produced by each salamander
46. Antibiotic resistance can vary within a population of bacteria. The diagram below represents the changes in a population of bacteria as a result of exposure to an antibiotic over time.
The changes in the population are most likely the result of which of the following?
A. exponential growth
B. genetic crosses
C. immigration
D. natural selection
47. The fossil record supports which of the following descriptions of the evolution of life on Earth?
A. Life first appeared with the diversity found today.
B. The importance of natural selection diminished over time.
C. Complex organisms evolved from more simple organisms.
D. Large organisms appeared before single-celled organisms.
48. Cladograms are diagrams that represent evolutionary relationships among organisms. These relationships are determined by comparing certain characteristics. The table below indicates the presence (+) or absence (–) of some characteristics in four organisms.
Jaws
Hair
Limbs
Placenta
Cat
+
+
+
+
Worm
-
-
-
-
Lizard
+
-
+
-
Fish
+
-
-
-
Based on the table, which cladogram shows the most likely evolutionary relationships among the four organisms? Options are presented in the order A, B, C, D.
49. A student researching bears found the chart below in a textbook. The chart shows the classifications of several types of bears.
Which of the following conclusions is best supported by the data given in this chart?
A. Modern bears evolved from species that are now extinct.
B. The short-faced bear was the ancestor of the Asiatic black bear.
C. Present day bear species are more closely related than their ancestors were.
D. Natural selection favored the brown bear over the American black bear.
ANSWERS
1 - D
2 - B
3 - See scored sample answers here
4 - B
5 - B
6 - D
7 - B
8 - A
9 - B
10 - B
11 - C
12 - A
13 -
14 - A
15 - D
16 - B
17 - D
18 - B
19 - C
20 - C
21 - D
22 - C
23 - B
24 - B
25 - C
26 - See scored sample answers here
27 - C
28 - B
29 - D
30 - B
31 - B
32 - A
33 - C
34 - C
35 - C
36 - See scored sample answers here
37 - D
38 - C
39 - D
40 - D
41 - B
42 - B
43 -
44 - A
45 - C
46 - D
47 - C
48 - A
49 - A
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