The limbs of vertebrates are an example of homologous structures. The vertebrate limbs have many features that resemble each other.

1. Carefully examine the drawings of the bones. Look for similarities among the various animals.
2. Copy the images into your notes and print them.
3. Color the human bones according to the color scheme below:
• Green = humerus
• Red = radius
• Blue = ulna
• Yellow = metacarpals
• Purple = phalanges
4. Then color the corresponding bone in each of the other animals the same color as the human bone.

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Check Your Answer

Use your notes to explain how these similarities in structures provides evidence of descent from a common ancestor.