Sometimes the change in allelic frequency is so different in the new sample of the population that they become a different species. The original drifted population create a different population. This is called

Options

A. Founder effect
B. Bottleneck effect
C. Metapopulation effect
D. Gene migration

Answer

To solve the question, we need to identify the phenomenon described in the statement regarding changes in allelic frequency leading to the formation of a new species. Let's break it down step by step.

### Step-by-Step Solution:

1. **Understanding Allelic Frequency**:
- Allelic frequency refers to how often a particular allele appears in a population. Changes in these frequencies can lead to significant evolutionary changes.

**Hint**: Consider how genetic variation can change when a population is separated or isolated.

2. **Identifying the Population Change**:
- The question describes a scenario where a new sample of the population has a different allelic frequency compared to the original population. This can happen due to various evolutionary mechanisms.

**Hint**: Think about what happens when a small group of individuals breaks away from a larger population.

3. **Concept of Genetic Drift**:
- Genetic drift is a mechanism of evolution that refers to random changes in allelic frequencies, especially in small populations. It can lead to the establishment of new populations with different genetic makeups.

**Hint**: Reflect on how genetic drift can lead to significant changes in small populations over time.

4. **Founder Effect**:
- The founder effect is a specific type of genetic drift that occurs when a small number of individuals from a larger population establish a new population. This small group may carry only a fraction of the genetic variation present in the original population, leading to different allelic frequencies.

**Hint**: Consider how the genetic diversity of the new population might differ from the original due to the limited number of founders.

5. **Conclusion**:
- Given the context of the question, the correct term for the phenomenon described is the **Founder Effect**. This effect illustrates how a new population can become genetically distinct from its original population due to the limited genetic variation carried by the founding individuals.

### Final Answer:
The phenomenon described in the question is called the **Founder Effect**.