Snakes do not possess legs because `:`

Options

A. Legs are lost during their entry in tunnels
B. Legs are lost during their evolution
C. The ancestors of reptiles did not have legs
D. Lizards do not possess legs

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks why snakes do not possess legs. To answer this, we need to explore the evolutionary history of snakes and their ancestors.

2. **Analyzing the Options**:
- **Option A**: "Legs are lost during their entry in tunnels." This option suggests that snakes lost their legs as a result of adapting to tunnel environments. However, this does not explain the evolutionary history of snakes.
- **Option B**: "Legs are lost during their evolution." This option implies that over time, through evolutionary processes, snakes lost their legs. This is a plausible explanation.
- **Option C**: "The ancestors of reptiles did not have legs." This option is incorrect because fossil records indicate that the ancestors of snakes did have legs.
- **Option D**: "Lizards do not possess legs." This option is misleading as lizards do have legs; they are a separate group of reptiles.

3. **Fossil Evidence**: Fossil records show that snakes' ancestors had a complete set of forelimbs and hindlimbs. This indicates that legs were present in their evolutionary lineage.

4. **Evolutionary Changes**: Over time, mutations and the disuse of limbs due to their mode of locomotion (creeping) led to the gradual loss of legs in snakes. The evolutionary principle states that if an organ is not used, it may diminish or disappear over generations.

5. **Conclusion**: Based on the analysis, the correct answer is that snakes do not possess legs because "legs are lost during their evolution."

**Final Answer**: Legs are lost during their evolution.

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