Writing A Scientific Argument

Amplify Science
Natural Selection
Chapter 4 Lesson 3

2. NS 4.3.1 WARM-UP
What if we only had one piece of evidence?
Would any of these pieces of evidence support the claim on their
own?
Yes, but the reasoning is more difficult because the link from the
evidence to the claim is not as clear without two pieces of evidence.

3. If I were supporting Claim 1
with Evidence Cards A and B, I
might say “Dogs still act like
wolves in many ways.
For example, dogs can smell
prey from far away, and wolves
can, too.”
NS 4.3.1 WARM-UP
Dogs still act like wolves in many
ways. For example, dogs can smell
prey from far away, and wolves
can, too.
I could add reasoning by saying
“This matters because both dogs
and wolves share a common
ability.”
Today, while you’re using the Reasoning Tool and writing
about the sticklebacks, think about which pieces of
evidence you might combine. Combining evidence is one
way to make a stronger argument.

4. NS 4.3.1 WARM-UP

5. NS 4.3.2 USING THE REASONING TOOL
In the last lesson, you
discussed claims and evidence
about why the stickleback
population changed over 13
generations. After the Science
Seminar, some of you may have
changed your thinking.
Today, you are going to develop
your own argument that
answers this question for Alex
Young’s colleagues. Dr. Young
already knows that the
sticklebacks had less armor
and became faster over time,
but she needs your help
explaining why.

6. NS 4.3.2 USING THE REASONING TOOL
When making an argument, you are
trying to explain your thinking in a
way that convinces someone else
that it is the best possible argument.
This practice is called reasoning.
Your argument needs to
include reasoning in order
for it to be convincing.

7. NS 4.3.2 USING THE REASONING TOOL
Today, you will complete a
paper version of the
Reasoning Tool.
First, you will write your
claim in the right column.
Then, you will tape the
evidence cards that support
your claim to the left
column.
Finally, you will use the
middle column to explain
how the evidence relates to
the claim.

8. NS 4.3.2 USING THE REASONING TOOL
Claim 1:The
sticklebacks have less
armor so that they can
escape predators.
Claim 2:The
sticklebacks have less
armor so that they can
catch prey.

9. NS 4.3.2 USING THE REASONING TOOL
Claim 1:The
sticklebacks have less
armor so that they can
escape predators.
Claim 2:The
sticklebacks have less
armor so that they can
catch prey.

10. NS 4.3.3 PREPARING TO WRITE
Identifying your strongest
piece of evidence is a
good idea because
convincing arguments
often start with the
strongest piece of
evidence.
Draw a circle
around your
strongest piece of
evidence.

11. NS 4.3.3 PREPARING TO WRITE
If there is a piece of
evidence on your
Reasoning Tool that does
not support your claim,
then draw an X over it.
That way, you will ignore it
when you begin writing
your argument.
Draw an X over a
piece of evidence
if you do not plan
to use it in your
argument.

12. NS 4.3.3 PREPARING TO WRITE
Drawing an arrow to
connect two pieces of
evidence will remind you
to put these pieces of
evidence together as you
structure your written
argument.
Draw an arrow to
connect two
pieces of evidence
if you think that
they go together.

13. NS 4.3.3 PREPARING TO WRITE
READY…..
GO!
Annotate YOUR
Reasoning Tool.

14. NS 4.3.4 WRITING A SCIENTIFIC ARGUMENT
Your Reasoning Tool has
helped you carefully
consider how the
evidence supports your
claim. You will now use
what you have already
written to expand on
your ideas. Remember,
you should refer to your
Reasoning Tool as you
write, but also be sure to
expand on your ideas
and use complete
sentences.

15. NS 4.3.4 WRITING A SCIENTIFIC ARGUMENT
Refer to these
sentence starters
to connect your
ideas and
articulate your
sentences more
clearly.

16. NS 4.3.4 WRITING A SCIENTIFIC ARGUMENT

17. NS 4.3.5 HOMEWORK
Students finish their written arguments and revise them so they
are as clear as possible.

18. NS 4.3.6 SELF-ASSESSMENT