Question

Which of the following factors produce and redistribute variations?
A. Mutation
B. Natural selection
C. Gene flow
D. Recombination
Choose the correct answer from the options given below:

• A. A, C and D only
• B. A, B and C only
• C. B and D only
• D. B, C and D only

Hint:

To remember the evolutionary forces, categorize them:
{Creates new variation:} Mutation
{Shuffles/Redistributes variation:} Recombination, Gene Flow
{Filters/Changes frequencies of variation:} Natural Selection, Genetic Drift

Answer 1

The Correct Option is A

Step 1: Concept Overview:
Evolution is driven by processes that introduce, shuffle, and filter genetic variation within and between populations. Identify the factors that produce new genetic variation or redistribute existing variation into new combinations.
Step 2: Detailed Analysis:
- A. Mutation: The primary source of new genetic variation. Mutation changes the DNA sequence, creating new alleles, and thus produces variation.
- B. Natural selection: A mechanism acting on existing variation. Differential survival and reproduction favor certain traits. Natural selection reduces or maintains variation; it neither produces nor redistributes it.
- C. Gene flow: The transfer of alleles between populations via migration. It redistributes variation by introducing alleles from one population's gene pool into another's.
- D. Recombination: Occurring during meiosis (crossing over), this process shuffles existing alleles on chromosomes, creating new combinations in offspring. A major source of genetic shuffling, it redistributes variation.
Step 3: Conclusion:
Mutation (A) generates new variation. Gene flow (C) and Recombination (D) redistribute existing variation. Natural selection (B) filters variation, but doesn't create or redistribute it. Therefore, A, C, and D are the correct factors.