In which period, life started shifting from water to land ?

Options

A. Ordovician
B. Silurian
C. Devonian
D. Permian

Answer

To determine in which period life started shifting from water to land, we need to analyze the given options based on the evolutionary history of life on Earth.

1. **Ordovician Period**:
- This period is part of the Paleozoic era. During the Ordovician, the first primitive land plants began to appear. However, life did not fully transition from aquatic environments to terrestrial habitats during this time. The Ordovician period is primarily known for marine life, and while some plants began to colonize land, the significant shift had not yet occurred.
- **Conclusion**: This option is incorrect.

2. **Silurian Period**:
- The Silurian period is also part of the Paleozoic era. This is the period where significant evolutionary changes occurred, leading to the transition of life from water to land. The conditions in aquatic habitats became less favorable, prompting organisms to explore terrestrial environments, which offered new opportunities for survival and evolution.
- **Conclusion**: This option is correct as it marks the beginning of life’s shift from water to land.

3. **Devonian Period**:
- The Devonian period is known for the evolution of four-legged amphibians. By this time, life had already adapted well to terrestrial habitats, but it was not the initial period of the shift. The Devonian is often referred to as the "Age of Fishes," and while significant advancements occurred, the shift had already begun in the previous period.
- **Conclusion**: This option is incorrect.

4. **Permian Period**:
- The Permian is the last period of the Paleozoic era. By this time, many life forms had already transitioned to land habitats. The Permian period is characterized by the dominance of reptiles and the diversification of terrestrial life, but it does not represent the initial shift from water to land.
- **Conclusion**: This option is incorrect.

**Final Answer**: The period in which life started shifting from water to land is the **Silurian Period**.