Molecular clock is related to

Options

A. Different sedimentary rocks in different ages
B. Evolution of different brain proteins
C. Evolution of satellite DNA in different organisms
D. Time required for origin and accumulation of mutations to form new species.

Answer

**Step-by-Step Solution:**

1. **Understanding the Molecular Clock Concept**: The molecular clock is a method used to estimate the time of evolutionary events based on the rate of genetic mutations. It operates on the premise that mutations accumulate in a species' DNA at a relatively constant rate over time.

2. **Analyzing the Options**: The question provides four options related to the molecular clock. We need to evaluate each option to determine which one accurately describes the concept of the molecular clock.

- **Option A**: Different sedimentary rocks in different ages - This relates to geological time but does not pertain to molecular evolution.
- **Option B**: Evolution of different brain proteins - While proteins can evolve, this option does not capture the essence of the molecular clock.
- **Option C**: Evolution of satellite DNA in different organisms - This is related to genetic studies but not specifically to the concept of a molecular clock.
- **Option D**: Time required for the origin and accumulation of mutation to form new species - This option directly relates to the molecular clock as it involves measuring the time taken for mutations to accumulate, leading to speciation.

3. **Selecting the Correct Answer**: After analyzing the options, it is clear that Option D is the correct answer as it encapsulates the essence of the molecular clock, which is about the timing of mutations and their role in the evolution of new species.

4. **Conclusion**: The molecular clock is fundamentally about understanding the time scale of evolutionary changes through the accumulation of genetic mutations. Therefore, the answer to the question is Option D.

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