Evolutionary History 3.1 & 3.2

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Evolutionary History
Lesson 3.1: Exploring
Relatedness

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Activity 1
Warm-Up

Page 79

10 MIN

Evolutionary History: Lesson 3.1

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Investigation Notebook pg 79

Activity 1 - Screen 1

Evolutionary History: Lesson 3.1

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Activity 1 - Screen 2

Evolutionary History: Lesson 3.1

What new features did you notice in this
evolutionary tree from the Warm-Up?

Poll

Which group of descendant species is most likely to have body structures that are the most different from the ancestor population?

• Descendant Species 1 & 2

• Descendant Species A, B, C, & D

Multiple Choice

Which descendant species is most likely to have body structures that are the most different from Descendant Species B?

• Descendant Species 1

• Descendant Species C

• Descendant Species A

​Complete page 79 NOW with the information you just entered for the previous questions

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Evolutionary History: Lesson 3.1

Remember, we are trying
to place the Mystery
Fossil in the museum,
and the museum’s
exhibits are set up so
that related organisms
are grouped together.

Activity 1 - Screen 2

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Chapter 3 Question

Evolutionary History: Lesson 3.1

How can we tell if the Mystery Fossil is more
closely related to wolves or to whales?

Activity 1 - Screen 2

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Evolutionary History: Lesson 3.1

What does it mean to be related to someone?

How do most people define this word?

Let’s discuss how we use the word “related” in everyday life.

Activity 1 - Screen 2

Open Ended

What does it mean to be related to someone? How do most people define this word?

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Vocabulary

Evolutionary History: Lesson 3.1

sharing a common ancestor population

related

Activity 1 - Screen 2

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Evolutionary History: Lesson 3.1

On an evolutionary tree, two species that
branched off more recently are more closely
related.

Activity 1 - Screen 2

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Which two species are most closely related
among Descendant Species A, B, and C?

Evolutionary History: Lesson 3.1

Activity 1 - Screen 2

Multiple Choice

Which two are most closely related between A, B, & C?

• A & B

• B & C

• A & C

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Key Concept

Evolutionary History: Lesson 3.1

6. Among any three species, the two species

that separated most recently are the most
closely related to each other.

Activity 1 - Screen 2

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Activity 3
Modeling Shared
Structures in Common
Ancestors

Page 83

15 MIN

Evolutionary History: Lesson 3.1

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Activity 3

Evolutionary History: Lesson 3.1

Next, you’ll use the
Modeling Tool to share
your ideas about how to
tell which species are
more closely related to
each other than to other
species.

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Activity 3

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Activity 3

Evolutionary History: Lesson 3.1

You will be given three
imaginary species and
practice using shared
structures to place them
on an evolutionary tree.

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Activity 3

Evolutionary History: Lesson 3.1

You’ll use the New
Structure panel to show
when a new structure
appeared on the tree.

You can select the row
with that structure
highlighted in blue.

Home

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Activity 3

Evolutionary History: Lesson 3.1

Next, we’ll discuss and
complete the Modeling
Tool as a class.

As we place the species,
we’ll share our thinking.

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Activity 3

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Investigation Notebook pg 83

Activity 3

Evolutionary History: Lesson 3.1

Multiple Choice

From Species C, D, & E, which pair of species is most closely related?

• C & D

• D & E

• C & E

​Complete page 83 NOW with the information you just entered for the previous question.

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Activity 3

Evolutionary History: Lesson 3.1

When trying to decide the relationships
between species, paleontologists look for
structures that are shared by one pair or group
of species but not by other species.

They sometimes call these diagnostic shared
structures because they help scientists make
decisions about relatedness.

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Activity 3

Evolutionary History: Lesson 3.1

In this example, back limbs (legs) could be
called a diagnostic shared structure. They
helped us diagnose that Species C and E
share a more recent common ancestor with
each other than with Species D.

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Activity 3

Evolutionary History: Lesson 3.1

Species share diagnostic
structures because they
are all descendants from
a common ancestor with
this structure.

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Activity 4
Homework

Page 84

Evolutionary History: Lesson 3.1

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Activity 4 - Screen 1

Evolutionary History: Lesson 3.1

For this activity, you will:

● compare two models

of evolutionary trees.

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Investigation Notebook pgs 84–85

Activity 4 - Screen 1

Evolutionary History: Lesson 3.1

Poll

Which model do you think is correct?

• Model 1

• Model 2

Open Ended

Explain how the two trees are different and why you think the model you indicated above is the correct one. (Hint: Use these words in your explanation: shared structure, related, inherit, descendant species, ancestor population)

​Complete page 84 NOW with the information you just entered for the previous questions.

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Evolutionary History
Lesson 3.2: Determining Species
Relatedness

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Activity 1
Warm-Up

Page 87

5 MIN

Evolutionary History: Lesson 3.2

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Investigation Notebook pg 87

Activity 1

Evolutionary History: Lesson 3.2

Multiple Choice

Where should Species C be placed on the tree?

• Space 1

• Space 2

Multiple Choice

What is the BEST body structure to use to make your decision?

• skull

• backbone

• tail

• front limb

• back limb

Open Ended

Explain how this body structure helped you make your decision.

​Complete page 87 NOW with the information you just entered for the previous questions.

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Activity 2
Investigating the
Relatedness of Extinct
Whales

Page 88-89

25 MIN

Evolutionary History: Lesson 3.2

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Remember, we’re investigating this question:

Activity 2

Evolutionary History: Lesson 3.2

Investigation Question:
When you compare different species, how can you tell
which species are more closely related than others?

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Activity 2

Evolutionary History: Lesson 3.2

Let’s think back to the model you
created yesterday.

What ideas do you have
so far about how
paleontologists decide
how closely species are
related?

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Activity 2

Evolutionary History: Lesson 3.2

We are working to place
the Mystery Fossil in a
section of the museum
where it will be near other
types of organisms that it
is closely related
to—either whales or
wolves.

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Activity 2

Evolutionary History: Lesson 3.2

Knowing the process
paleontologists use to
tell how closely species
are related will help us
place the Mystery Fossil.

Let’s watch a video about
this process.

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Activity 2

Evolutionary History: Lesson 3.2

Next, you’ll use the Sim
to practice the process
paleontologists use to
place species on an
evolutionary tree.

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Activity 2

Evolutionary History: Lesson 3.2

This time, you’ll launch
the Sim in a new mode
called Cetaceans.

Then, you’ll open Tree
View and use the Tree
Navigation menu to go to
the Cetaceans branch.

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Activity 2

Evolutionary History: Lesson 3.2

Remember, cetaceans is
the group that includes
whales.

You’ll begin by studying
the structures of two
living whales: blue
whales and orcas.

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Activity 2

Evolutionary History: Lesson 3.2

Then, you’ll place these
five cetacean species on
the evolutionary tree by
deciding which species
are more closely related.

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Investigation Notebook pg 88

Activity 2

Evolutionary History: Lesson 3.2

The empty spaces on the
evolutionary tree are
numbered from 1 to 5.

These are the locations
where you’ll place the
species.

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Investigation Notebook pg 88

Activity 2

Evolutionary History: Lesson 3.2

For each empty space on
the tree, you’ll consider
two species and decide
which one to place there.

There are hints about
which body structures to
study.

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Activity 2

Evolutionary History: Lesson 3.2

To study the structures
and make your decision,
you’ll need to open the
Study windows for both
species and look at the
Structures tab.

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Activity 2

Evolutionary History: Lesson 3.2

Let’s consider Location 1
together.

We’ll discuss whether to
place Dorudon or
Kutchicetus on that
branch of the
evolutionary tree.

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Activity 2

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Activity 2

Evolutionary History: Lesson 3.2

Now, you and your
partner will discuss and
place all five cetacean
species on the
evolutionary tree.

Remember to use the
Study windows for help.

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Investigation Notebook pgs 88–89

Activity 2

Evolutionary History: Lesson 3.2

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Investigation Notebook pg 89

Activity 2

Evolutionary History: Lesson 3.2

Discuss the reflection
question, and then write
your answers.

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Investigation Notebook pg 94

Activity 2

Evolutionary History: Lesson 3.3

What are the diagnostic
structures in both whales
and wolves?

What structures do they
not share?

Multiple Choice

Which of these two species belongs in Location 1?

• Dorudon

• Kutchicetus

Multiple Choice

Which of these two species belongs in Location 2?

• Pakicetus

• Kutchicetus

Multiple Choice

Which of these two species belongs in Location 3?

• Indohyus

• Ambulocetus

Multiple Choice

Which of these two species belongs in Location 4?

• Pakicetus

• Indohyus

Open Ended

Which species is dorudon more closely related to: the blue whale or Ambulocetus? Which diagnostic structure(s) could you use to show this?

​Complete page 88 & 89 NOW with the information you just entered for the previous questions.

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Activity 3

Evolutionary History: Lesson 3.2

Key Concept

7. When two species share a structure that is

not shared with a third species, this can be
evidence that the first two species are more
closely related to each other than to the
third species.

​You should have these pages completed in your workbook by the end of this lesson:

79

83

84

87

88

89

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End of Lesson

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Evolutionary History: Lesson 3.2