Non-Systemic Evolutionary Force
Which is not a systemic force?
- Random Genetic drift — Correct Answer
- Migration
- Mutation
- Selection
Explanation:
Correct Answer: Random Genetic Drift
Forces that alter gene frequencies are classified as systemic or dispersive. Random genetic drift (Sewell Wright effect) is a dispersive force — not a systemic one.
Systemic vs Dispersive Forces
| Feature | Systemic Forces | Dispersive Forces |
|---|---|---|
| Examples | Mutation, Migration, Selection | Random Genetic Drift (Sewell Wright effect) |
| Population size | Large and small populations | Only in small populations |
| Predictability | Can be predicted in amount AND direction | Can be predicted only in amount, NOT direction |
Speed of Gene Frequency Change
- Fastest: Selection
- Slowest: Mutation (rate: 10⁻⁵ to 10⁻⁶ per locus per generation)
- Random Genetic Drift: Acts unpredictably; can fix or eliminate alleles in small populations rapidly
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
