Life Science: Evolution
Teacher’s Guide
Grade Level: 6–8
Curriculum Focus: Life Science
Lesson Duration: 2 class periods
Program Description
Charles Darwin’s theory of evolution is the unifying concept in biology. As the video points out,
overwhelming evidence supports natural selection. Although some disagree with the theory, pesticideresistant insects, modern elephants, Darwin’s Galápagos finches, and adaptive virus strains prove that
natural selection is happening all the time. Examine the evolution of the elephant over its 50 million
year history to see how it evolved from a small, pig-like animal to the behemoth we know today. Visit
the Galápagos Islands to see a living “laboratory” of natural selection, and unearth the latest
discoveries in the islands’ fossils. Darwin knew his ideas would shake the world. But it’s evolution that
shaped the living things on it.
Discussion Questions
•
What are evolution and natural selection?
•
Explain events that led Charles Darwin to develop his theory. When was On the Origin of Species
published and what public reaction did it elicit?
•
What famous trial decided whether evolution could be taught in Tennessee classrooms?
•
Describe the evolution of the elephant from its 50-million-year-old ancestor to today.
•
What are some reasons the Galápagos Islands are an excellent place to study natural selection?
•
In studying the fossils of the Galápagos, what event seems to be the cause of extinctions on the
islands?
Lesson Plan
Student Objectives
•
Understand the concepts of evolution and natural selection.
•
Examine the Galápagos finches and draw conclusions about them based on beak adaptations.
•
Speculate on how humans might adapt to live on another planet and define adaptations that
would help them survive.
Life Science: Evolution
Teacher’s Guide
2
Materials
•
Computer with Internet access
•
Print resources about evolution and natural selection
•
Paper and markers or computer drawing program
Procedures
1. Review with the class the concepts of evolution and natural selection. Then guide students
through a classic case in point by allowing them to examine Darwin’s Galápagos finches in
much the same way he must have.
2. Familiarize students with the 14 species of finches on the Galápagos Islands. These Web sites
will come in handy:
•
Adaptive Radiation and Endemic Species on Islands slideshow
http://www.abdn.ac.uk/zoohons/lecture5/
•
BBC’s Bitesize page The Theory of Evolution, a good overall primer
http://www.bbc.co.uk/schools/gcsebitesize/biology/variationandinherit
ance/3evolutionrev2.shtml
•
PBS’s “Evolution” page Adaptation Radiation: Darwin’s Finches
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_02.html
and the interactive page An Origin of Species
http://www.pbs.org/wgbh/evolution/darwin/origin/
•
Rochester Institute of Technology’s Darwin’s Finches
http://www.rit.edu/~rhrsbi/Galápagos Pages/DarwinFinch.html
•
Scientific American article “Adaptive Radiation of Darwin’s Finches”
http://chiron.valdosta.edu/jbpascar/Courses/Biol1010/ExtraCreditActivities/America
n Scientist Online - Adaptive Radiation of Darwin's Finches.htm
3. Ask students to examine the different Galápagos finch species with particular emphasis on the
beaks. Looking at the beaks and comparing them to bird species students are familiar with can
help students determine what types of foods the different species might eat. Ask them to sort
the birds into categories based on food choice. You can find charts that show this on PBS’s
Darwin’s Finches page and in the Scientific American article. Discuss how the 14 species
originated from one common ancestor. What advantages would birds that were able to eat
different foods have over those that all ate the same thing?
4. Explore how natural selection might work in a fantasy environment. Pose to the class that
humans are to be sent to five different planets, each with very different living conditions.
Assume that each planet can support life, some better than others. First, brainstorm conditions
on the five planets. Then assign one planet to a group of students. The group’s job is to
Published by Discovery Education. © 2005. All rights reserved.
Life Science: Evolution
Teacher’s Guide
speculate about what adaptations would help humans thrive in their new world. Create an
illustration of what the inhabitants of the planet might look like in several million years and
write up a brief profile about them. Answer these questions:
•
What planetary conditions might prompt adaptation?
•
What foods are available?
•
What adaptations would give people an advantage on the planet?
•
How might living on the planet change humans physically?
•
What types of behavior changes might be advantageous?
5. When students have completed their initial profiles, ask them to share them with the group.
Vote on which group of transplanted humans seem best adapted for life on their planet.
Assessment
Use the following three-point rubric to evaluate students’ work during this lesson.
•
3 points: Students were highly engaged in class discussions and produced a complete
profile, including all of the requested information.
•
2 points: Students participated in class discussions and produced an adequate profile,
including most of the requested information.
•
1 point: Students participated minimally in class discussions and created an incomplete
profile with little or none of the requested information.
Vocabulary
adaptation
Definition: A physical or behavioral change that improves a species’ ability to succeed in its
environment
Context: The adaptation of night vision has helped the swallowtail gull survive amid other gull
species that don’t have this ability.
adaptive radiation
Definition: Diversification from a common ancestor into different forms
Context: Darwin’s finches are a perfect example of adaptive radiation: From one ancestor, 14
different species evolved, each filling a different role in the environment.
artificial selection
Definition: Human intervention in breeding animals or plants with desired characteristics
Context: Darwin noted that horses had been artificially selected and bred for speed.
evolution
Definition: Process by which an organism changes over time, generally to become more
successful
Published by Discovery Education. © 2005. All rights reserved.
3
Life Science: Evolution
Teacher’s Guide
4
Context: The process of evolution can be seen in the elephant’s 50-million-year history.
natural selection
Definition: The natural process by which organisms better suited for their environment survive
to pass those qualities on to successive generations.
Context: According to natural selection, the fastest cheetah will be a better hunter and survive to
pass her genes on.
niche
Definition: A specific area or function within a habitat
Context: Darwin’s finches adapted to exploit different niches—such as seedeaters or insect
eaters—in their environment.
Scopes Trial
Definition: The trial in 1925 in which teacher John Scopes was found guilty of violating
Tennessee law by teaching evolution.
Context: The Scopes Trial was headline news in its day, and the law prohibiting the teaching of
evolution in Tennessee schools wasn’t overturned until 1967.
Academic Standards
National Academy of Sciences
The National Science Education Standards provide guidelines for teaching science as well as a
coherent vision of what it means to be scientifically literate for students in grades K–12. To view the
standards, visit this Web site:
http://books.nap.edu/html/nses/html/overview.html#content
This lesson plan addresses the following national standards:
•
Life Science: Regulation and behavior; Diversity and adaptations of organisms
Mid-continent Research for Education and Learning (McREL)
McREL's Content Knowledge: A Compendium of Standards and Benchmarks for K–12 Education
addresses 14 content areas. To view the standards and benchmarks, visit
http://www.mcrel.org/compendium/browse.asp
This lesson plan addresses the following national standards:
•
Science: Life Sciences—Understands biological evolution and the diversity of life
•
Language Arts: Viewing—Uses viewing skills and strategies to understand and interpret
visual media; Writing—Uses the general skills and strategies of the writing process, Gathers
and uses information for research purposes; Reading—Uses reading skills and strategies to
understand and interpret a variety of informational texts
Published by Discovery Education. © 2005. All rights reserved.
Life Science: Evolution
Teacher’s Guide
5
Support Materials
Develop custom worksheets, educational puzzles, online quizzes, and more with the free teaching tools
offered on the Discoveryschool.com Web site. Create and print support materials, or save them to a
Custom Classroom account for future use. To learn more, visit
•
http://school.discovery.com/teachingtools/teachingtools.html
Find more Discovery lesson plans devoted to evolution at
Evolution Explorations
•
http://school.discovery.com/lessonplans/programs/lifestory/
Galápagos : Beyond Darwin
•
http://school.discovery.com/lessonplans/programs/Galápagos -beyonddarwin/
Published by Discovery Education. © 2005. All rights reserved.