What evidence supports the hypothesis that whales evolved from land dwelling mammals?

Explanation

### Step-by-Step Text Solution:

1. **Introduction to the Hypothesis**: The hypothesis that whales evolved from land-dwelling mammals is supported by various pieces of evidence from anatomy, fossil records, and genetics.

2. **Vestigial Structures**: One of the most compelling pieces of evidence is the presence of vestigial pelvic bones in modern whales. These bones are remnants of the pelvic structure found in their land-dwelling ancestors, suggesting that these animals once had the ability to walk on land.

3. **Comparative Anatomy**: The bones in the flippers of whales are structurally similar to the limb bones of land mammals. For example, the flippers contain the same types of bones (humerus, radius, and ulna) that are found in the forelimbs of terrestrial mammals, indicating a common ancestry.

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