Question

Which one of the following characteristics is NOT true for 'genetic drift'?

• A. It usually does not occur in a large random mating population
• B. It is as like to genetic erosion
• C. It leads to the loss of alleles
• D. It is almost inevitable in a small population

Hint:

Genetic drift is a random, statistical genetic process, whereas genetic erosion is a broad ecological and agricultural phenomenon describing the systematic loss of crop landraces and wild relatives.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Genetic drift is an evolutionary mechanism characterized by random changes in allele frequencies across generations due to chance events (sampling error) in small populations.

Step 2: Detailed Explanation:
Let us evaluate each of the statements to identify the incorrect one:
- Statement A: In large, randomly mating populations, sample sizes are sufficiently large that allele frequencies remain stable from generation to generation according to Hardy-Weinberg equilibrium. Thus, genetic drift is negligible. This statement is true.
- Statement C: Because allele frequency shifts are random, alleles can drift toward a frequency of 0 (loss) or 1 (fixation). This reduces genetic variation within a population. This statement is true.
- Statement D: In small populations, sampling error is pronounced, making significant random fluctuations in allele frequencies inevitable over time. This statement is true.
- Statement B: "Genetic erosion" is the progressive loss of genetic diversity within a species, often due to human activities (e.g., habitat destruction, monoculture farming, or replacement of local landraces with modern cultivars). While both processes involve a loss of alleles, genetic drift is a stochastic, natural evolutionary force driven by population size, whereas genetic erosion refers to a broader conservation issue. They are distinct concepts and cannot be considered "alike".

Step 3: Final Answer:
Hence, the statement "It is as like to genetic erosion" is NOT true.