Which of the following is an example of coevolution ?

Options

A. Barnacle and whale
B. Clown fish and sea anemone
C. Hermit crab and sea anemone
D. Bees and orchid flower

Answer

To determine which of the following is an example of coevolution, we need to understand the concept of coevolution itself. Coevolution refers to the process where two or more species influence each other's evolutionary trajectory. This often occurs in relationships where species are interdependent, such as mutualism, where both species benefit from the interaction.

### Step-by-Step Solution:

1. **Define Coevolution**: Coevolution is the process where two species evolve in response to changes in each other. This means that the evolutionary changes in one species directly affect the other.

2. **Identify Relationships**: Look for relationships where two species are closely linked and affect each other's evolution. Examples include predator-prey relationships, mutualistic relationships, and parasitic relationships.

3. **Evaluate Examples**:
- **Bees and Orchid Flowers**: Bees pollinate orchids while obtaining nectar. The evolution of the bee's foraging behavior can influence the evolution of the orchid's flower structure, and vice versa. This is a classic example of coevolution because both species adapt to each other’s changes.
- **Barnacles and Whales**: Barnacles attach to whales for transportation. This is a commensal relationship where barnacles benefit, but whales are not affected. There is no coevolution here since the whale does not evolve in response to the barnacle.
- **Clownfish and Sea Anemone**: Clownfish live among sea anemones, gaining protection while providing nutrients to the anemone. This is another example of mutualism, but it does not necessarily indicate coevolution as both species may not significantly influence each other's evolutionary path.
- **Hermit Crab and Sea Anemone**: Similar to clownfish and sea anemones, this relationship is also commensal, where one benefits without affecting the other.

4. **Conclusion**: Based on the evaluation, the relationship between bees and orchid flowers is the best example of coevolution, as both species are interdependent and influence each other's evolution.

### Final Answer:
The example of coevolution is the relationship between bees and orchid flowers.