An example of species-specific coevolution is -

Options

A. Yucca plants and the single species of moth that pollinates them
B. Fig species and its pollinating species of wasp
C. Both a and b
D. Hydrilla and its pollinating agent

Answer

To determine an example of species-specific coevolution, we will analyze the options provided and identify the correct answer based on the definitions and relationships involved in coevolution.

### Step-by-Step Solution:

1. **Understand Coevolution**: Coevolution refers to the process where two or more species influence each other's evolutionary trajectory. This often occurs in mutualistic relationships where both species benefit from their interactions.

2. **Identify Species-Specific Coevolution**: Species-specific coevolution occurs when two species evolve in direct response to each other, often seen in obligate mutualism, where one species cannot survive without the other.

3. **Analyze the Options**:
- **Option 1: Yucca plant and single species of moth that pollinate them**: This is a classic example of species-specific coevolution. The yucca plant relies on a specific moth for pollination, and the moth relies on the yucca for reproduction.
- **Option 2: Fig species and its pollinating species of wasps**: This is also an example of species-specific coevolution. The fig tree and the wasp have a mutualistic relationship where the wasp pollinates the fig while laying its eggs inside the fig.
- **Option 3: Boat A and B**: This option does not provide a biological example and is likely irrelevant to the question.
- **Option 4: Hydrilla and its pollinating agent**: While this may involve a relationship, it is not as specific as the previous examples and does not represent a well-documented case of coevolution.

4. **Select the Best Examples**: Both Option 1 and Option 2 represent clear cases of species-specific coevolution. However, if we need to choose one, we can highlight the relationship between the yucca plant and the moth as a textbook example.

5. **Final Answer**: The best example of species-specific coevolution from the options provided is **Option 1: Yucca plant and single species of moth that pollinate them**.