Extra-terrestrial origin of life was proposed by theory of

Options

A. Catastrophism
B. Spontaneous generation
C. Special creation
D. Panspermia

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks about the theory that proposes the extra-terrestrial origin of life, meaning life originated from outside Earth.

2. **Identifying the Relevant Theory**: The theory that supports the idea of life coming from outer space is known as the **Panspermia Theory**. This theory suggests that life, in the form of spores or simple organisms, was transported to Earth from other parts of the universe.

3. **Explaining Panspermia**: According to the Panspermia theory, life did not originate on Earth but was brought here by cosmic dust or meteorites. These spores or germs could have survived the journey through space and eventually evolved into the diverse forms of life we see today.

4. **Alternative Names and Concepts**: Panspermia is also referred to as the **Cosmozoic Theory** or **Spore Theory**. It posits that life exists throughout the universe and can travel between celestial bodies.

5. **Criticism of the Theory**: Although Panspermia provides an interesting perspective, it has been criticized. Scientists argue that living organisms may not survive the harsh conditions of space, such as extreme cold, dryness, and high levels of ultraviolet radiation.

6. **Conclusion**: Based on the information provided, the correct answer to the question is that the extra-terrestrial origin of life was proposed by the **Panspermia Theory**.

**Final Answer**: The extra-terrestrial origin of life was proposed by the theory of **Panspermia**.

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