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Warm-Up Evolutionary Relationships

Lesson Question

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WK2 Words to Know

Fill in this table as you work through the lesson. You may also use the glossary to help you.

a single organism from which other organisms have descended

a branching diagram that depicts the evolutionary relationships among species

a group of organisms that can mate and produce offspring that can mate

a feature or quality

Evolution

Evolution is the process of change in a over time.

Comparative

Lesson Goals

Examine how evolutionary relationships can be modeled and interpreted.

Interpret evolutionary relationships among organisms on a cladogram.

Analyze the relationships among organisms based on a variety of

characteristics.

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Evolutionary RelationshipsInstruction

Characteristics

• Characteristics are the features or of an organism

or .

• Organisms that are related to each other have many

characteristics in common.

Shared Characteristics

• There are diff erent types of shared characteristics.

• Characteristics that existed in the common , have

remained unchanged, and still exist in organisms

• Characteristics that have been from what was found in the common ancestor

Circle the common characteristic among the three organisms in the table.

Characteristic Frog Turtle Bird

Hard-shelled egg X X

Scaly skin X X

Backbone X X XBackbone

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Evolutionary RelationshipsInstruction

5Slide

Cladograms

• A cladogram is a diagram that shows evolutionary relationships.

• The closer the branches on the cladogram, the more closely related the

/species.

Circle the common ancestor for A, B, and C in both the diagrams.

Circle the group that contains a common ancestor and all the descendants.

On a cladogram, branches that are together and farther up on the

cladogram are always more closely related than the branches that are farther

apart and on the cladogram.

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Evolutionary RelationshipsInstruction

8Slide

Cladograms and Shared Characteristics

Circle the organisms that are the most closely related in the given table.

Characteristic Lamprey Gorilla Tiger Shark Lizard Salamander

Jaws X X X X X

Lungs X X X X

Dry skin X X X

Hair X X

No tail X

Tiger

How to Make a Cladogram

Circle the branch after which all organisms have lungs, and underline the branch after which all organisms have hair.

If the line is not diagonal, then the organism on the far left is going to be the

most . This suggests the is the most primitive, or

ancient, of the organisms.

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Evolutionary RelationshipsInstruction

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Cladograms and Shared Characteristics

The characteristics that are used must be shared among the .

In order for a to be used in a cladogram, it must be

to all organisms above a particular point on the cladogram.

Cladogram Construction

Circle the organism having one characteristic in the table.

Underline the organism having all the characteristics in the table.

Characteristic Lily Moss Fern Conifer

tissueX X X

X

Seeds X X

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Summary Evolutionary Relationships

Answer

Review: Key Concepts

• Shared are features or qualities that organisms or

species have in common.

• There are two different types of shared characteristics.

• Characteristics that existed in the common ancestor, have remained

, and still exist in modern organisms

• Characteristics that have been modified from what was found in the

common

• that are closely related to each other have many

characteristics in common.

Lesson Question How can evolutionary relationships be modeled and interpreted??

2Slide

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Summary Evolutionary Relationships

Review: Key Concepts

• are branching diagrams that show evolutionary

relationships.

• They are developed using characteristics.

Use this space to write any questions or thoughts about this lesson.

2Slide