Which one of the following promotes similarity among living things ?

Options

A. Adaptation
B. Natural selection in different environments
C. Inheritance from a common ancestor
D. Homeostatic regulation

Explanation

To answer the question "Which one of the following promotes similarity among living things?" we need to analyze the options provided and understand the concepts related to them.

### Step-by-Step Solution:

1. **Understanding Adaptation**:
- Adaptation refers to the changes that organisms undergo to fit into their changing environments.
- These changes are specific to the environment and do not promote similarity among different organisms.
- **Conclusion**: Adaptation does not promote similarity.

2. **Understanding Natural Selection**:
- Natural selection is a process where certain traits become more common in a population because they provide a survival advantage.
- While it influences the traits of organisms, it does not inherently promote similarity among different species.
- **Conclusion**: Natural selection does not promote similarity.

3. **Understanding Inheritance from Common Ancestors**:
- This concept refers to the idea that organisms that share a common ancestor will have similar traits or structures, even if they have diverged over time.
- This is known as divergent evolution, where homologous structures (similar in structure but different in function) arise from a common ancestor.
- Examples include the forelimbs of mammals like humans, whales, and birds, which have similar bone structures but serve different functions.
- **Conclusion**: Inheritance from common ancestors promotes similarity among living things.

4. **Understanding Homeostasis Regulation**:
- Homeostasis refers to the regulation of an organism's internal environment to maintain stable conditions despite external changes.
- While important for survival, it does not promote similarity among different species.
- **Conclusion**: Homeostasis regulation does not promote similarity.

### Final Answer:
The correct answer is **inheritance from common ancestors**, as it promotes similarity among living things through shared traits derived from a common ancestor.

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