THEORY OF EVOLUTION

Name ____________________________________________ Class: 5 7 9 Date________________________
CHAPTER 15 ACTIVE READING WORKSHEETS
THEORY OF EVOLUTION
Section 15-1: History of Evolutionary Thought
Read the passage below, which covers topics from your textbook. Answer the questions that
follow.
Darwin used the phrase descent with modification to describe the process of evolution. He carefully
reviewed the evidence that every species—living or extinct—must have descended by reproduction
from preexisting species and that species must be able to change over time. Darwin was not the
first person to put forward the idea of descent with modification, but he was the first to argue that
all species had descended from only one or a few original kinds of life. Darwin saw the animals of
the Galápagos Islands as evidence of descent with modification. For example, the islands are home
to 13 similar species of finches. Each of these bird species has a beak that is best adapted for a
certain kind of food. But Darwin suspected that all 13 species descended from and diverged from
just a few ancestral finches. These ancestors could have flown to the Galápagos Islands from
elsewhere sometime after the islands were formed.
Read each question and write your answer in the space provided.
SKILL: Identifying Main Ideas
1. What is descent with modification as used by Darwin? _______________________________
___________________________________________________________________________
2. What evidence supporting Darwin’s descent with modification is contained in the passage? _____________
______________________________________________________________________________
Circle the letter of the phrase that best completes the sentence.
3. According to Darwin’s descent with modification, organisms
a. can exist in only one particular geographic location.
b. give rise to similar organisms.
c. do not change over time.
d. Both (a) and (b)

THEORY OF EVOLUTION
Section 15-2: Evidence of Evolution
Read the passage below, which covers topics from your textbook. Answer the questions that
follow.
In 1668, Robert Hooke published his conclusion that fossils are the remains of plants and animals.
Hooke was one of the first scientists to study fossils, principally petrified wood, with the aid of a
microscope.
Hooke thought the detail he saw with the microscope was too fine and precise to have been formed
by the rock itself. He hypothesized that living organisms had somehow been turned to rock.
Hooke’s view was shared by another scientist of his time, Nicolaus Steno. In 1669, Steno proposed
the principle of superposition, which states that successive layers of rock or soil were deposited
on top of one another by wind or water. The lowest stratum, or layer, in a cross section of Earth is
the oldest, while the top stratum is the most recent. Thus, fossils within a single stratum are of the
same approximate age. Using Steno’s principle, observers could establish the relative age of a
fossil; that is, they could say that a given fossil was younger or older than another fossil. The fossil’s
absolute age (its age in years) could be estimated from the amount of sediment deposited above
the fossil or by using the radiometric dating of a nearby rock layer.
Fill in the blank to complete each sentence.
SKILL: Sentence Completion
One reading skill is the ability to complete an incomplete sentence by logically determining
what will complete the unfinished thought.
1. Robert Hooke was one of the first scientists to study fossils through a _________________________________________ .
2. His observations led Hooke to conclude that fossils are the remains of ________________________________________ .
3. According to the principle of superposition, fossils in the same stratum are about _______________________ .
Circle the letter of the word or phrase that best completes the statement.
4. The top stratum in a cross section of Earth is the
a. youngest.
b. layer most likely to contain fossils.
c. oldest.
d. Both (a) and (b)

THEORY OF EVOLUTION
Section 15-3: Evolution in Action
Read the passage below, which covers topics from your textbook. Answer the questions that
follow.
The change of two or more species in close association with each other is called co
evolution. Predators and their prey sometimes co evolve, parasites and their hosts often co
evolve, and plant eating animals and the plants they feed on also co evolve. One example of co
evolution is plants and the animals that pollinate them. Sometimes, organisms that appear to be
very similar, such as a shark and a porpoise, are not closely related at all. This kind of similarity is
the result of convergent evolution. Convergent evolution occurs when the environment selects
similar phenotypes, even though the ancestral types were quite different from each other.
Analogous structures, such as similar fins in very different animals, are associated with convergent
evolution.
In divergent evolution, two or more closely related populations or species become more
and more dissimilar. Divergence is nearly always a response to differing environments, and it can
ultimately result in new species. Sometimes, the process of divergence can be sped up artificially
through artificial selection. All domestic dogs are the same species, Canis familiaris. Dogs have
been bred by humans for certain phenotypic characteristics, resulting in different breeds with
different traits.
Refer to the passage to complete the graphic organizer below.
SKILL: Organizing Information
Patterns of Evolution
Evolution Pattern Example
1. 3. Parasites & their hosts
Convergent evolution 4. 5.
2. 2 or more related species 6.
or populations become
more and more
dissimilar, often due to
differing habitats
P
Circle the letter of the word or phrase that best completes the sentence.
7. Artificial selection can sometimes speed up the process of
a. convergent evolution.
b. co evolution.
c. divergent evolution.
d. Both (a) and (b)erns of Ev

Modern Biology Vocabulary Review
In the space provided, write the letter of the term or phrase that best completes
each statement or best answers each question.
______ 1. The process in which organisms with traits well suited to an environment
are more likely to survive and to produce offspring is
a. trait mechanisms. c. genetic principles.
b. origin of species. d. natural selection.
______ 2. Most scientists agree that
a. Earth is about 3.5 million years old. b. life is new on Earth.
c. living organisms share ancestry. d. intermediate fossils do not exist.
______ 3. A change in the genetic makeup of species over time is called
a. radioactive dating. c. camouflage.
b. evolution. d. fossilization.
______ 4. The process by which a species becomes better suited to its environment is
a. artificial selection. c. adaptation.
b. not an advantage. d. destructive to its survival.
______ 5. Structures that share a common ancestry or are similar because they are modified
versions of structures from a common ancestor are
a. not related. c. not homologous.
b. homologous. d. young in origin.
______ 6. Structures with no function that are remnants of an organism’s evolutionary past
are
a. not visible on organisms. c. vestigial.
b. young in origin. d. useful to the organism.
______ 7. Species that share a common ancestor
a. have many amino acid sequence differences.
b. have few amino acid sequence differences.
c. have identical nucleotide sequences.
d. are not represented by the fossil record.
______ 8. Individuals that have traits that enable them to survive in a given environment can
reproduce and
a. begin the process of co evolution.
b. pass on those traits to their offspring.
c. slow the process of evolution.
d. All of the above

______ 9. Populations of a species that now differ genetically because they have adapted to
different living conditions have undergone
a. convergent evolution. c. adaptive radiation.
b. artificial selection. d. coevolution.
______10. Which of the following statements was NOT suggested by Darwin?
a. Natural selection is the mechanism that drives evolution.
b. Antibiotic-resistant strains of bacteria have evolved by natural
selection.
c. There are many examples of how natural selection has shaped life
on Earth.
d. The beak shapes of the finches of the Galápagos are determined by
natural selection.
______11. Which of the following is a factor in natural selection?
a. Individuals of a species compete with one another to survive.
b. All species are genetically diverse.
c. Individuals better able to adapt to changes leave more offspring.
d. All of the above
______12. When a species permanently disappears, the species is said to be
a. extinct. b. rare. c. adapted. d. eliminated.
______13. The adaptation of bacteria to survive the effects of antibiotics is called
a. resistance. b. convergence. c. divergence. d. elimination.
______14. The fossil record provides evidence that
a. older species gave rise to more-recent species.
b. all species were formed during Earth’s formation and have
changed little since then.
c. fossilized species have no connection to today’s species.
d. fossils cannot be dated.
______15. Individuals that are better able to cope with the challenges of their environment
tend to
a. decrease in population over time.
b. leave more offspring than those more suited to the environment.
c. leave fewer offspring than those less suited to the environment.
d. leave more offspring than those less suited to the environment.
______16. The pelvic bones of modern whales no longer function like the pelvis of a land
vertebrate and are an example of
a. an analogous structure. c. a vestigial structure.
b. a homologous structure. d. coevolution.