EH 2.5 (3/2) Version B

Launch Evolutionary History Modeling Tool activity: Population Changes.

In the Modeling Tool, a population is divided into two populations in different environments. In each environment, different structures are useful for survival.

Goal: Show how the body structures of the populations in each environment might change over time.

Do:

• Read the information at the top of the screen.

• Move organisms from the toolbar to the open locations in both branches of the tree.

• Press INDICATE ORGANISM TYPE and select an option for each organism.

Tip:

• You do not have to use all the organisms in the toolbar.

As you know, whales, wolves, and the Mystery Fossil have shared structures, but those structures look very different from one another. Today you will work with your group and use the Word Relationships Cards to create sentences that answer the question: How did wolves, whales, and the Mystery Fossil become so different from their common ancestor population?

• Use at least two different words in each sentence.

• You do not need to use all the vocabulary words.

• There are many different ways to answer the Chapter 2 Question, and you will need to create more than one sentence in order to express your ideas completely.

CFS:

• student describes the relationship between anatomical similarities and differences in animal species

• student describes the environmental difference between animal species with a common ancestor based on body structures

Word bank:

common ancestor population descendant species evolutionary time. shared structure speciation