How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Biology
AP Bio. Enduring Understanding
1.A. Change in the genetic makeup
of a population over time is
evolution.
Bio.3.4.1 Explain how fossil, biochemical,
and anatomical evidence support the
theory of evolution. 5F/H7
Bio.2.2.1 Infer how human activities
(including population growth, pollution,
global warming, burning of fossil fuels,
habitat destruction and introduction of
nonnative species) may impact the
environment.
Bio.3.4.2 Explain how natural selection
influences the changes in species over
time. 5F/H6
Bio.3.2.3 Explain how the environment
can influence the expression of genetic
traits.5F/H6; 6B/H1
Bio.1.2.3 5F/H3; Explain how
specific adaptations help cells survive
in particular environments (focus on
unicellular organisms).
Bio.2.1.2 Analyze the survival and
reproductive success of organisms in
terms of behavioral, structural, and
reproductive adaptations. 5F/H3;
How does genetic information provide evidence for evolution?LS4.A
Genetic information, like the fossil record, also provides evidence of evolution. DNA sequences vary
among species, but there are many overlaps; in fact, the ongoing branching that produces multiple lines of
descent can be inferred by comparing the DNA sequences of different organisms. Such information is also
derivable from the similarities and differences in amino acid sequences and from anatomical and
embryological evidence. Anatomical similarities and differences among various organisms living today are
compared to those of organisms in the fossil record in order to reconstruct evolutionary history and infer
lines of evolutionary descent. Organisms resemble their ancestors because genetic information (DNA) is
transferred from ancestor to offspring during reproduction. The branching that characterizes lines of descent
can be inferred from the DNA composition of organisms over time. The similarities and differences in DNA
sequences, amino acid sequences, anatomical evidence, and fossil evidence provide information about the
branching sequence of lines of evolutionary descent.
How does variation of organisms help them survive and reproduce as environments change?LS4-B
Natural selection can occur only if there is variation in the genetic information between organisms of the
same species in a population and variation in the expression of that genetic information as a trait. Genetic
variation within a population influences the likelihood that a population will survive and produce offspring.
Sexual reproduction not only allows the continuation of traits in a population but also provides a source of
genetic variation among the individuals of a population through genetic recombination. The expression of
new anatomical, physiological and behavioral traits in organisms within a population can result from
recombining existing genes. It also can occur by random sorting during sex cell production and fertilization.
Variation within a population of organisms can also result from genetic mutations that create variation in
the expression of traits between organisms of the same species. In artificial selection, humans have the
capacity to influence certain characteristics of organisms by choosing parents’ desired characteristics,
determined by genes, which in turn are passed on to their offspring.
How can different environmental factors lead to changes in populations of organisms?LS4-C
Natural selection leads to a diversity of organisms that are anatomically, behaviorally and physiologically
well suited to survive and reproduce in a specific environment. Over time, the differential survival and
reproduction of organisms within a population that have an advantageous heritable trait lead to an increase
in the proportion of individuals in future generations that have the trait and a decrease in the proportion of
individuals that do not. Changes in the abiotic environment, including climatic and geological processes,
have contributed to the decline of some species and the expansion of other species. When environmental
change—naturally occurring or human induced—happens, extinction can occur. Species become extinct
because they cannot survive and reproduce in their environments. If members cannot adjust—because
change in the environment is too fast or too drastic—they die or become unable to reproduce, thus
closing off the opportunity for evolution. Charles Darwin’s theory of evolution had a dramatic effect on
biology because of his use of clear and understandable argument and the inclusion of a massive array of
evidence to support the argument. Later evidence continues to support and refine this theory.
What is the current threat to biodiversity given human impact? How will changes in biodiversity affect
humans? LS4-D
Humans depend on the living world. The resources and benefits provided by the living world are considered
“ecosystem services.” Biodiversity results from the formation of new species (speciation) minus extinction.
Biodiversity is seriously threatened by human impact in the form of habitat destruction, over-exploitation,
damage by invasive species, and climate change. These have the potential to cause a major pulse of
biological extinctions. Biological extinction is a critical factor in reducing biodiversity because it is
irreversible. Sustaining biodiversity so productivity and ecosystem functioning remain is essential to
maintaining and enhancing the quality of life of the growing human population.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
6-8
To Biology
8.L.4.1 Summarize the use of
evidence drawn from geology, fossils,
and comparative anatomy to form
the basis for biological classification
systems and the theory of evolution.
5F/M2,4
Grades 6 – 8
8.L.4.2 Explain the relationship
between genetic variation and an
organism’s ability to adapt to its
environment. 5F/M2,4
8.L.3.1 Explain how factors such as
food, water, shelter, and space affect
populations in an ecosystem. 5D/M1a
7.L.2.3 Explain the impact of the
environment and lifestyle choices on
biological inheritance (to include common
genetic diseases) and survival. 5F/M2a,b
6.L.2.3 Summarize how the abiotic factors (such
as temperature, water, sunlight, and soil quality)
of biomes (freshwater, marine, forest, grassland,
desert, Tundra) affect the ability of organisms to
grow, survive and/or create their own food
through photosynthesis. 5D/M1b
What does the fossil record tell us about the history of life on Earth?LS4A
Fossils are mineral replacements, preserved remains, or traces of organisms that lived in the past. Thousands of
layers of sedimentary rock not only provide evidence of the history of Earth itself but also of changes in
organisms whose fossil remains have been found in those layers. The collection of fossils and their placement in
chronological order (e.g., through the location of the sedimentary layers in which they are found or through
radioactive dating) is known as the fossil record. It documents the existence, diversity, extinction, and change of
many life forms throughout the history of life on Earth. Because of the conditions necessary for their
preservation, not all types of organisms that existed in the past have left fossils that can be retrieved.
Anatomical similarities and differences between various organisms living today and between them and organisms
in the fossil record enable the reconstruction of evolutionary history and the inference of lines of evolutionary
descent. Comparison of the embryological development of different species also reveals similarities that show
relationships not evident in the fully formed anatomy.
How can differences influence which organisms survive and reproduce? LS4B
Genetic variations among individuals in a population give some individuals an advantage in surviving and
reproducing in their environment. This is known as natural selection. It leads to the predominance of certain traits
in a population and the suppression of others. In artificial selection, humans have the capacity to influence certain
characteristics of organisms by selective breeding. One can choose desired parental traits determined by genes,
which are then passed on to offspring. Changes in environmental conditions can affect the survival of individual
organisms and entire species. Individuals with certain traits are more likely than others to survive and have
offspring. In sexually reproducing organisms, each parent contributes half of the genes acquired (at random) by
the offspring.
How does variation of traits influence how populations of organisms can change? LS4C
Natural selection arises from three well established observations: (1) There is genetically-based variation in traits
within every species of organism, (2) some of these traits give some individuals advantage over others in survival
and reproduction, and (3) those individuals that survive to adulthood will be more likely to have offspring which
will themselves be more likely than others to survive and reproduce. When an environment changes, the
advantage or disadvantage of characteristics can change. Adaptation by natural selection acting over generations
is one important process by which species change over time in response to changes in environmental conditions.
Traits that support successful survival and reproduction in the new environment become more common; those
that do not become less common. Thus, the distribution of traits in a population changes. In separated populations
with different conditions, the changes can be large enough that the populations, provided they remain separated
(a process called reproductive isolation), evolve to become separate species.
What happens when the diversity of life changes? LS4D
Biodiversity is the wide range of existing life forms that have adapted to the variety of conditions
on Earth, from terrestrial to marine ecosystems. Biodiversity includes genetic variation within a species, in
addition to species variation in different habitats and ecosystem types (e.g., forests, grasslands, wetlands).
Changes in biodiversity can influence humans’ resources, such as food, energy, and medicines, as well as
ecosystem services that humans rely on—for example, water purification and recycling.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
3-5
To 6.L.2.3
Grades 3 – 5
5.L.3.1 Explain why organisms differ
from or are similar to their parents
based on the characteristics of the
organism. 5F/E1
Why do individuals of the same species vary in how they look, function, and
behave?LS3A
Offspring acquire a mix of traits from their biological parents. Different organisms
vary in how they look and function because they have different inherited
information. In each kind of organism there is variation in the traits themselves, and
different organisms may have different versions of the trait. The environment also
affects the traits that an organism develops—differences in where they grow or in
the food they consume may cause organisms that are related to end up looking or
behaving differently.
4.L.1.4 Explain how differences among
animals of the same population
sometimes give individuals an advantage
in surviving and reproducing in changing
habitats. 5D/E1;5F/E1
4.E.2.1 Compare fossils
(including molds, casts,
and preserved parts of
plants and animals) to one
another and to living
organisms. 5F/E2
3.L.2.2 Explain how environmental
conditions determine how well plants
survive and grow. 5D/E1
3.L.2.1 Remember the function of the following
plant structures as it relates to the survival of
plants in their environment:(Roots – absorb
nutrients; Stems – provide support; Leaves –
synthesize food; Flowers – attract pollinators and
produce seeds for reproduction (5F/E1)
4.E.2.2 Infer ideas about
Earth’s early
environments from fossils
of plants and animals that
lived long ago.
Many characteristics of organisms are inherited from their parents. Other
characteristics result from individuals’ interactions with the environment, which can
range from diet to learning. Many characteristics involve both inheritance and
environment.
What can fossils tell us about the past? LS4A
Scientists have identified many plants, animals, and fungi. There are also many
kinds of living organisms that can only be seen with a microscope. Fossils provide
evidence about the types of living organisms, both visible and microscopic, that
lived long ago and the nature of the environments in which they lived. Fossils can
be compared to one another and to living organisms according to their similarities
and differences.
How do differences between individuals matter? LS4B
Individuals of the same kind differ in their characteristics. Sometimes the
differences in characteristics between individuals of the same species provide
advantages in surviving, finding mates, and reproducing.
What happens to organisms when their environment changes? LS4C
Changes in an organism’s habitat are sometimes beneficial to it and
sometimes harmful. For any particular environment, some kinds of plants and
animals survive well, some survive less well, and some cannot survive at all.
What happens when there are changes in the ecological conditions of places
where organisms or groups of organisms live? LS4D
Scientists have identified many plants, animals, and fungi. There are also many
kinds of living things that can only be seen with a microscope. Organisms and
populations of organisms live in a variety of habitats. Humans, like all other
organisms, get living and non-living things (e.g., resources) from their
environments. Change in habitats can be good, bad, or neither good nor bad (i.e.,
neutral) for a species. Some plants and animals no longer exist on Earth (e.g.,
dinosaurs).
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
K-2
2.L.2.2 Recognize that there is
variation among individuals that are
related. (5B/P1)
To 3.L.2.1
Grades K – 2
How do we know plants and animals lived a long time
ago?LS4A
Fossils provide evidence about plants and animals that lived
long ago. Some kinds of plants and animals that once
2.L.2.1 Identify ways in which plants and
animals closely resemble their parents in
observed appearance and ways they are
different. (5A/1; 5B/P2)
lived on Earth (e.g., dinosaurs) are no longer found
anywhere, although others now living (e.g.,lizards)
resemble them in some ways.
Are there differences among individuals of the same kind?
LS4B
There is variation among living things of one kind within a
population.
Supporting Objective 1.L.1.2
Different plants and animals have external
features that help them thrive in different kinds
of places. 5F/1
What can influence the survival of living things? LS4C
Living things can survive only in environments in which
their needs are met. The world has many environments and
distinct environments support different types of living
things. If some places are too hot or too cold or have
too little water or food, plants and animals may not be
able to live there.
1.L.1.2 Give examples of how the needs of different
plants and animals can be met by their environments in
North Carolina or different places throughout the
world.5D/P2
Where do different kinds of living things live? LS4D
There are many different kinds of living things in any
area, and they exist in different places on land and in
water. Different kinds of plants and animals live in
different places and need different things to live. Sometimes
there are changes in the places where plants and animals
live.
K.L.1.2 Compare characteristics of animals in terms of living and
nonliving things in terms of their: Structure. Growth. Changes.
Movement. Basic needs. 5A/P1 Supporting Objectives
Variation and
Advantage
Inherited Characteristics
Evidence from fossils and
existing organisms
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Natural Selection AP Bio. Enduring Understanding 1.A.
Change in the genetic makeup of a population over time is
evolution.
1.A.4: Biological evolution is supported by scientific evidence
from many disciplines, including mathematics.
In a hypothetical population of beetles, there is a wide
variety of color, matching the range of coloration of the
tree trunks on which the beetles hide from predators.
The graphs below illustrate four possible changes to the
beetle population as a result of a change in the
environment due to pollution that darkened the tree
trunks.
Which of the following includes the most likely change
in the coloration of the beetle population after pollution
and a correct rationale for the change?
(See attached item.)
Bio.3.4 Explain the theory of evolution by natural
selection as a mechanism of change over time in
species.
Bio.3.4.1
Scientist often study fossil records to learn about
species that lived long ago. Which is true about living
species and extinct species that scientists may observe
in fossil records?
a. If a species living today and an extinct species
have many similarities, they could share a common
ancestor, but if they have few similarities they
could not share a common ancestor.
b. A species living today and an extinct species
could share a common ancestor that lived a very
long time ago, even if the two species have few
similarities.
c. No species living today could share a common
ancestor with an extinct species.
d. Species living today could share a common
ancestor with each other, but extinct species could
not share a common ancestor with each other
because extinct species are the ancestors of species
living today, never of each other
What other evidence would scientist most likely use to
support this claim?
Bio.3.4 Explain the theory of evolution by natural
selection as a mechanism for how species change
over time.
Bio.3.4.2 During the Industrial Revolution, there
were two variations of English Peppered Moths,
those with light color and those with dark color. The
soot from the factories covered the trees. Data was
collected to measure the percentage of each type of
moth in the area. It was noted that the percentage of
dark-colored moths increased over time, while the
percentage of light-colored moths decreased. What is
the likely explanation for this change?
a. The presence of a mutation changed the color of
the English Peppered Moths.
b. The presence of the dark-colored variation
increased the likelihood for survival of the
English Peppered Moths.
c. The presence of the light-colored variation
increased the likelihood for survival of the
English Peppered Moths.
d. The presence of an acquired trait changed the
color of the English Peppered Moths.
Bio.3.2 Understand how the environment, and/or
the interaction of alleles, influences the
expression of genetic traits.
Bio.3.2.3 A population is a group of individuals of the
same species. Could a population living today differ
from their ancestors from many generations ago? Why
or why not?
a. Yes, they could differ after many generations
because an environmental change can cause
individuals in each generation to try to change some
of their inherited traits to ones that are better suited
to the new environment.
b. Yes, they could differ after many generations
because an environmental change can affect
which inherited traits are most helpful, and
therefore which individuals are more likely to
survive and reproduce.
c. Yes, they could differ after many generations
because an environmental change can cause
individuals to use some of their inherited traits more
than before and pass down better versions of those
traits to their offspring.
d. No, they could not differ after many generations
because all members of a population are the same
species and therefore have the same set of inherited
traits.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Natural Selection
Bio. 2.1 Analyze the interdependent relationships of living
organisms within their environments.
Bio.2.1.2 The following species of bird ate many types of seeds,
each type coming from a different species of tree. The birds'
beaks varied in size, with some individuals having slightly
smaller beaks and others having slightly larger beaks.
A few years went by without much rain, and the only
species of tree that survived had large seeds. Many
generations later, almost all the birds had the slightly larger
beaks. How is this best explained?
a. The birds with larger beaks were better at eating
the large seeds than those with smaller beaks, so only
the birds with larger beaks got enough food to survive,
reproduce, and pass the trait of large beaks to the next
generation.
b. The birds with smaller beaks had to work harder than
those with larger beaks to crack open the large seeds. The
more they used their beaks, the larger their beaks became,
so they were able to get enough food to survive, reproduce,
and pass the traits of large beaks to the next generation.
c. The birds with smaller beaks grew their beaks so that
they would be better able to eat the large seeds and get
enough food to survive, reproduce, and pass the trait of
larger beaks to the next generation.
d. It was a chance occurrence that all the individual birds'
beaks in the next generation were larger. They were
therefore able to eat the large seeds and get enough food to
survive, reproduce, and pass the trait of large beaks to the
next generation.
8.L.4 Understand the evolution of organisms and
landforms based on evidence, theories and
processes that impact the earth over time.
8.L.3 Understand how organisms interact with
and respond to the biotic and abiotic components
of their environment.
8.L.4.2 The different species of Hawaiian
honeycreepers now have different beaks, eat different
foods, sing different songs, and live in different
environments on the islands.
Two researchers wanted to see if they could
observe natural selection at work. They decided to
bring the birds to a new home. The new home they
designed would have some of the characteristics of
each of the birds’ old environment; however, some
changes would be harsh and very different.
8.L.3.1 Habitat Change Vol. 2 pg. 143
A small, short furred, gray animal called a divo lives
on an island. This island is the only place on Earth
where divos live. The island habitat is warm and
provides plenty of the divos’ only food. – tree ants.
The divos live high in the treetops, hidden from
predators.
Which statement best predicts what will happen to the
birds?
a. none of the birds will try to adapt to the change and
all of the birds will die
b. some of the birds will be able to adapt to the
change but some of the birds will die
c. all of the birds will be able to adapt to the change
because they have a common ancestor
d. all of the birds will try to adapt to the change
because they have a common ancestor
One year the habitat experienced a drastic change the
lasted for most of the year. It became very cold and
even snowed. All of the ants died. The trees lost their
leaves, but plenty of seeds and dried leaves were on
the ground.
Circle any of the things you think happened to most
of the divos living on the island after their habitat
changed.
a. The divos’ fur grew longer and thicker.
b. The divos switched to eating seeds.
c. The divos dug holes to live under the leaves or
beneath the rocks.
d. The divos hibernated through the cold period until
the habitat was warm again.
e. The divos died.
Explain your thinking. How did you decide what
effect the change in the habitat would have on most
of the divos?
7.L2 Understand the relationship of the
mechanisms of cellular reproduction, patterns of
inheritance and external factors to potential
variation among offspring.
The Pima Indians of Arizona are the descendants of
Pima Indians who reside in the Sierra Madre
mountains of Northern Mexico. Today 50% of the
Arizona Pima have diabetes compared to less than
1% for those living in the Sierra Madre mountains.
Which factor, environment, inheritance or lifestyle
choice, do you think is most responsible for this
comparison? Explain your choice and provide
evidence to support your choice.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Natural Selection
6.L.2 Understand the flow of energy through
ecosystems and the responses of populations to the
biotic and abiotic factors in their environment.
6.L.2 Understand the flow of energy through
ecosystems and the responses of populations to the
biotic and abiotic factors in their environment.
6.L.2.3 Which gas(es) do plants take in from their
environments? (you may circle more than one)
6.L.2.1Explain how the following living and
nonliving things are connected with each other:
(a) Grass
(b) Cows
(c) Human beings
(d) Decomposing bacteria
(e) Soil
(f) Energy from the sun
(g) Carbon dioxide
(h) Oxygen
oxygen
carbon dioxide
other
Explain what happens to the gases once they are inside
the plant.
Why do large trees have a difficult time living in a
Tundra?
a. A Tundra is too hot for trees to grow large.
b. Animals that live in a Tundra destroy most
vegetation.
c. Flooding occurs too often in a Tundra for
large trees to grow.
d. The soil in a Tundra is too nutrientpoor for large trees to grow.*
6.L.2.1 A small acorn grows into a large oak tree.
(a) Which of the following is FOOD for plants (circle
ALL correct answers)?
Soil
Air
Sunlight
Fertilizer
Water
Minerals in soil
Sugar that plants
make
(b) Where do you think the plant’s increase in weight
comes from?
5.L.3 Understand why organisms differ from or
are similar to their parents based on the
characteristics of the organism.
5.L.3.1 Sam’s dog had puppies. Three of the puppies
were black and two were white. The father dog was
black. The mother dog was white. Why are the dogs
different colors?
a. Puppies inherit more traits (genes) from their fathers
than their mothers.
b. The puppies got half their traits (genes) from their
father and half from their mother.
c. Male traits (genes) are stronger than female genes.
d. Black puppies have more traits (genes) than white
puppies.
Which friend do you most agree with and why?
Explain your thinking about heredity.
A student moved his pet rabbits from sunny Florida to
cold Alaska when they were all very small. Some of the
rabbits have long ears, good for hearing, and some have
short ears that help hold in heat. Once the rabbits were
moved to Alaska what do you think happened to the
rabbits that were born in Alaska.
a. All of the new rabbits will have short ears, because
Alaska is very cold.
b. Most of the new rabbits will have long ears, because
long ears are most fit for Alaska.
c. Some of the rabbits will have long ears and some
will have short ears, because they will look like their
parents.
d. All of the new rabbits will have short ears because
only rabbits with short ears can survive in Alaska.
Which friend do you most agree with and why?
Explain your ideas about heredity and adaptation.
4.L.1 Understand the effects of environmental
changes, adaptations and behaviors that enable
animals (including humans) to survive in
changing habitats.
4.L.1.4 Scientists study a bird called a warbler,
shown below, by placing small metal tags on the
birds’ legs.
One kind of warbler with black-and-white feathers
is often seen on tree trunks. Another kind with
golden-colored feathers is often seen in fields.
After a few years of extremely cold weather, the
fields died off and only trees were available for
shelter. Many generations later, scientists observed
that almost all the warbler birds had black-andwhite feathers and almost all the golden warblers
were gone. How is this best explained?
Friend 1: “I think most of the warblers are blackand-white because the golden-colored warblers
changed colors to hide from predators and survive.”
Friend 2: “I think most of the warblers are blackand-white because predators ate most of the goldencolored warblers.”
Friend 3: “I think most of the warblers are blackand-white because the golden-colored warblers died
from the cold weather.”
Which friend do you most agree with and why?
Explain your ideas about adaptation.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Natural Selection
3.L.2 Understand how plants survive in their
environments.
2.L.2. Remember that organisms differ from or are
similar to their parents based on the
characteristics of the organism.
1.L.1 Understand characteristics of various
environments and behaviors of humans that
enable plants and animals to survive.
K.L.1 Compare characteristics of animals that
make them alike and different from other
animals and nonliving things.
3.L.2.2 Four friends investigated four types of plants to
determine which would be best to plant in their butterfly
garden. This is what they each suggested:
2.L.2.2 Jamie and Mary visit the zoo. They see two
female tigers who are mother and daughter. Jamie
points out that the fur of one of the tigers has stripes
that are darker brown than the other tiger’s stripes.
Mary says the tigers cannot be mother and daughter.
1. L.1.2 Create a garden habitat that will attract and
provide the basic needs for birds, butterflies and
plants that are found in North Carolina. Research
and plant appropriate flowers.
K.L.1.2 The pictures below represent an owl, a
butterfly and a statue of an owl. What do the owl
and butterfly have in common and how are they
different? How is a living owl similar to the statue
and how are they different?
Friend 1: “Sample A, because they produce lots of roots
to absorb nutrients.”
Friend 2: “Sample B, because they produce colorful
flowers to attract butterflies.”
Friend 3: “Sample C, because they grow very tall.”
Friend 4: “Sample D, because they have very large dark
green leaves to make plenty of food.”
Which friend selected a characteristic that will most
likely enable the plants to survive in the butterfly
garden? Explain your choice.
How can Jamie explain to Mary that tigers with
different colored stripes can be mother and daughter?
In your answer use a specific example of what you
have observed about similarities and differences
between individuals who are related.
Have students research and draw habitats of similar
plants and animals that are found in other parts of
the world. Discuss differences and similarities (e.g.,
type of materials used to build each shelter) and
explain how each environment enables the different
plants and animals to survive.
Joey decided to create a garden habitat, exactly like
the one from school, in his backyard except he would
include plants and animals from other parts of the
world as well as those from NC. Which plants and
animals do you think will grow and survive best?
Explain your selections.
Living Owl
Living Butterfly
Statue of Owl
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and
microorganisms? Evolution of Life: Natural Selection & Biological Evolution
Multiple Choice Item
In a hypothetical population of beetles, there is a wide variety of color, matching the range of coloration
of the tree trunks on which the beetles hide from predators. The graphs below illustrate four possible
changes to the beetle population as a result of a change in the environment due to pollution that
darkened the tree trunks.
Which of the following includes the most likely change in the coloration of the beetle population after
pollution and a correct rationale for the change?
(A) The coloration range shifted toward more light-colored beetles, as in diagram I. The pollution
helped the predators find the darkened tree trunks.
(B) The coloration in the population split into two extremes, as in diagram II. Both the lighter-colored
and the darker-colored beetles were able to hide on the darker tree trunks.
(C) The coloration range became narrower, as in diagram III. The predators selected beetles at the
color extremes.
(D) The coloration in the population shifted toward more darker- colored beetles, as in diagram
IV. The lighter-colored beetles were found more easily by the predators than were the
darker- colored beetles
Essential Knowledge
1.A.4: Biological evolution is supported by scientific evidence from many disciplines, including
mathematics.
Science Practice
1.1: The student can create representations and models of natural or man-made phenomena and
systems in the domain.
Learning Objective
1.13: The student is able to construct and/or justify mathematical models, diagrams, or
simulations that represent processes of biological evolution.
How can there be so many similarities among organisms yet so many different kinds of plants, animals, and
microorganisms? Evolution of Life: Natural Selection & Biological Evolution
2013 AP® BIOLOGY FREE-RESPONSE QUESTIONS
Question 5
The table below shows the amino acid sequence of the carboxyl-terminal segment of a conserved
polypeptide from four different, but related, species. Each amino acid is represented by a threeletter abbreviation, and the amino acid residues in the polypeptide chains are numbered from the
amino end to the carboxyl end. Empty cells indicate no amino acid is present.
Species
I
II
III
IV
1
Val
Val
Val
Val
2
His
His
His
His
3
Leu
Leu
Leu
Leu
Relative Amino Acid Position
4
5
6
7
Val
Glu
Glu
His
Lys
Glu
Glu
His
Val
Glu
Glu
His
Val
Arg
Trp
Ala
8
Val
Val
Val
Cys
9
Glu
Glu
10
His
His
Met
Asp
(a) Assuming that species I is the ancestral species of the group, explain the most likely genetic change
that produced the polypeptide in species II and the most likely genetic change that produced the
polypeptide in species III.
(b) Predict the effects of the mutation on the structure and function of the resulting protein in species IV.
Justify your prediction.