The study of history of life forms on earth

Answer

**Step-by-Step Solution:**

1. **Identify the Subject Matter**: The question asks about the study of the history of life forms on Earth. This indicates that we are looking for a scientific field that focuses on the evolution and diversity of life.

2. **Define Evolutionary Biology**: Evolutionary biology is a subfield of biology that specifically studies the evolutionary processes that have led to the diversity of life on Earth. It examines how life forms have changed over time and the mechanisms behind these changes.

3. **Key Concepts in Evolutionary Biology**:
- **Natural Selection**: This is the process through which certain traits become more common in a population because they provide some advantage in survival or reproduction.
- **Common Descent**: This concept suggests that all living organisms share a common ancestor from which they have diverged over time.
- **Speciation**: This is the process by which new species arise from existing ones, often due to evolutionary pressures or environmental changes.

4. **Conclusion**: Given that evolutionary biology encompasses the study of the history and diversity of life forms on Earth through these processes, it is the correct answer to the question.

**Final Answer**: The study of the history of life forms on Earth is known as **evolutionary biology**.

---