Natural selection favours those allels which make the organisms better adapted to the environment. Under which condition the two alternative alleles make an organism equally well adapted?

Options

A. a.Genetic drift
B. b.In absence of predator
C. c.mutation
D. d.Bottle neck effect

Answer

To answer the question regarding the conditions under which two alternative alleles make an organism equally well adapted to the environment, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Natural Selection**: Natural selection is a process where certain alleles (gene variants) are favored because they provide better adaptation to the environment, leading to increased survival and reproduction of organisms carrying those alleles.

2. **Identifying the Context**: The question asks under what conditions two alternative alleles (for example, a dominant and a recessive allele) can make an organism equally well adapted. This implies that both alleles do not confer a significant advantage or disadvantage in a specific environment.

3. **Considering Environmental Factors**: One significant environmental factor that influences adaptation is the presence or absence of predators. Predators can exert selective pressure on populations, favoring alleles that enhance survival against predation.

4. **Absence of Predators**: In the absence of predators, there is less selective pressure on the population. This means that both alleles (dominant and recessive) can potentially lead to similar levels of fitness in the organisms. Without predators, the organisms can thrive regardless of which allele they possess.

5. **Conclusion**: Therefore, the condition under which the two alternative alleles make an organism equally well adapted is the absence of predators. In this scenario, natural selection does not favor one allele over the other, allowing both to coexist with equal adaptability.

### Final Answer:
The two alternative alleles make an organism equally well adapted in the absence of predators.

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