Cladograms and Dichotomous Keys

Cladograms

Early taxonomists classified organisms according to their physical features. Relying solely on physical characteristics, you might conclude that bats and birds are closely related because both organisms have wings. However, bats are actually more closely related to rodents than they are to birds. Why is it, then, that rodents such as mice do not have wings? In this interactivity, you will learn how diagrams called cladograms shows how species that share a common ancestor are related through inherited traits. Click the player button to begin.

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Dichotomous Keys

A dichotomous key is a classification tool used to identify and classify organisms according to defining characteristics. To identify organisms using a dichotomous key, you read a series of statements that describe traits and then determine whether the organism has the trait or not. In this interactivity, you will learn how to make a dichotomous key by classifying four hypothetical organisms. Click the player button to begin.

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Cladograms and Dichotomous Keys Review

Now that you have explored cladograms and dichotomous keys, it is time to review your knowledge and practice what you have learned. In this non-graded activity, read the questions or statements and select the appropriate answers. Click the player button to get started.