Science
SCI.III.4.1
Grade: 8th
Strand III:
Using Scientific Knowledge in Life Science
Standard 4:
Evolution - All students will explain how scientists construct and
scientifically test theories concerning the origin of life and
evolution of species; compare ways that living organisms are
adapted (suited) to survive and reproduce in their environments;
and analyze how species change through time.
Benchmark 1: Describe what biologists consider to be evidence for human
evolutionary relationships to selected animal groups.
Constructing and Reflecting:
SCI.I.1.1 – Ask questions that can be investigated empirically.
SCI.I.1.4 – Gather and synthesize information from books and other sources of information.
SCI.I.1.5 – Discuss topics in groups by making clear presentations, restating or summarizing what others have
said, asking for clarification or elaborating, taking alternative perspectives and defending a position.
SCI.II.1.2 – Describe some general limitations of scientific knowledge.
SCI.II.1.4 – Discuss the historical development of key scientific concepts and principles.
Vocabulary
Context
Common types of evidence used:
• Hominid fossils
• Vestigial structures
• DNA
• Protein structure
• Homologous structure
• Analogous structure
• Embryology
•
•
•
•
Skeletal comparisons:
¾ modern human to hominid fossils
Anatomical and biochemical similarities of
humans and other higher primates:
¾ blood proteins
Similarity of early human embryo stages to
those of other vertebrates
Vestigial structures:
¾ appendix
¾ tail bone
Knowledge and Skills
Students will:
• Analyze and interpret evidence supporting a
progression from a common ancestry.
•
Resources
Coloma Resources:
Book: Holt Science & Technology
Book C Chapter 5 pg 106-133
List and discuss what biologists consider to
be evidence that humans evolved from more
primitive forms.
Other Resources:
• Evolution and the Nature of Science Institute
Excellent site with units and lessons dedicated
to The Nature of Science, Evolution, The
Origin of Life and DNA.
•
Brain POP Movies
•
•
Scope Unit – Taxonomy of Evolution
http://www.michigan.gov/scope/0,1607,7-15513515_13516_13519-36176--,00.html
Michigan Teacher Network – 16 resources for
this benchmark
•
•
Howard Hughes Medical Institute – incredible
free resources
•
http://www.thirteen.org/wnetschool/origlessons/
evolution/ “Scopes monkey trial”
•
Chicago Museum of Natural History
•
PBS evolution series
•
Local University Professors
Instruction
• Compare amino acid sequences in proteins
(e.g. hemoglobin) of several vertebrates,
including humans. Study amino acid
differences and infer evolutionary
relationships among these vertebrates.
Corresponds to standard I.1.4
•
Students will trace the evolution of a product
such as cars, tennis shoes, TV or
computers, including a time line and pictures
of the product. Corresponds to standard
I.1.4
The teacher will present the following scenario:
An evolutionary biologist has been given the
following information about the amino acid
sequences of a protein (e.g., hemoglobin) found
in the following animals.
Working in pairs, students will write an essay
explaining how they might compare amino acid
sequences and describe the possible
evolutionary relationships between two animals.
(hemoglobin level table in MI-CliMB)
Assessment
•
Construct a tree diagram that shows the
evolutionary relationships among the
vertebrates investigated in the instructional
example. Back up your tree with supporting
evidence from the chart given in the
instructional example.
(Evaluation rubric available in MI-CliMB)
•
Time line showing the progression in the theory
of evolution. Corresponds to standard II.1.4.
Criteria Apprent Basic
Meets
Exceeds
Accuracy
of
evolutionary tree
diagram
Draws and
labels an
evolutionary tree
with more
than two
inaccuracies.
Draws and
labels an
evolutionary tree
with one
or two
inaccuracies.
Draws and
labels a
complete
and
accurate
evolutionary tree.
Draws and
labels a
complete
evolutionary
tree with
exceptional
quality.
Explanation of
evidence
Provides
inaccurate
evidence
for three or
more
branches
based on
chart.
Provides
inaccurate
evidence
for two
branches
based on
chart.
Provides
accurate
evidence
for all
branches
based on
chart.
Provides
accurate
evidence for
all branches
with
explanations.
Teacher Notes:
Focus Question: How do biologists evaluate evidence that humans evolved from more primitive
forms of life?
Explain how scientists construct and scientifically test theories concerning the origin of life
and evolution of species.
Are there patterns of similarity among organisms alive today? Are there relationships among organisms that
lived in the past and organisms alive today? Where did humans come from in the history of the world? What is
the evidence that might give us some clues to these questions? Many students come to the science classroom
with strongly held beliefs that don't allow them to openly examine the scientific explanations to these questions.
The challenge in the science classroom is to help students distinguish between a scientist's way of thinking and
understanding from those practiced by some theologians, poets, or philosophers.
Students need working definitions of key terms with clear examples to provide a framework for their thinking.
This should help them demarcate where science begins and ends. Words such as fact, theory, hypothesis, and
law are terms students encounter in casual conversation in everyday life. In science these terms have a very
specific meaning. A fact is an observation that has been repeatedly confirmed but facts can change. It was a
scientific fact for many years that human cells had 24 pairs of chromosomes. Improved techniques of
microscopy revealed that they actually have 23 pairs.
People commonly use the word theory to mean a "guess" or "hunch". "My theory is..." in common usage would
be better stated as "My hypothesis is....". In science, a hypothesis is a testable statement about the natural
world. A theory, in science, is a well-substantiated explanation of some aspect of the natural world. It is a
powerful idea that represents our best explanation at this time. The abundance of supporting evidence makes
the subsequent abandonment of a theory unlikely. Theories can be continually refined and even replaced with
an alternative theory in light of new and compelling evidence.
Finally, laws are generalizations that describe phenomena whereas theories explain phenomena. The laws of
thermodynamics describe what will happen under certain circumstances; thermodynamic theories explain why
these events occur. A clear understanding of these terms should provide students the structure needed to
begin the study of evolution.
It is important for students to be able to distinguish between evolution and the proposed mechanism, which
accounts for its occurrence. Evolution is the historical change in life forms that is well substantiated and is
generally accepted as fact by scientists. Students should explore the similarities of vertebrate's limb structures
such as the forelimb of a chicken or bat, human, whale, cat, and lizard. They may also study similarities in the
early development of vertebrate embryos. Students need an opportunity to observe, from the fossil record,
kinds of organisms that once lived on earth but now are extinct such as the Petoskey stone's, Hexagonaria
percarinata, trilobites, or crinoids. They can examine the apparent relatedness of fossils to one another and to
organisms living today. This will begin to lay the groundwork for evidence of common ancestry.
Students are naturally drawn to questions of their own ancestry. Students can perform a simple comparison for
similarities and differences when given pictures or models of a gorilla, a modern human, and a hominid fossil
skull. Patterns will emerge as students discover intermediate traits and forms. Further study of the relationships
of humans to other selected animal groups can be done by looking at DNA and blood protein similarities.
Vestigial structures such as the appendix, tailbone, wisdom teeth, and ear muscles also give evidence to
common ancestry with selected animal groups.
Teacher Notes: (con’t)
Patterns and evidence of change, as well as recognizing the diversity and apparent relatedness of species,
needs to be firmly established before delving into possible mechanisms for evolution. To better understand
natural selection students can survey the examples of artificial selection occurring today with common pets like
cats and dogs, or numerous agricultural products.