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Question #46469
The Question
In the context of industrial melanism observed in Biston betularia in England, which of the following conclusions is biologically INCORRECT regarding the evolutionary dynamics of this population?
Options
- A.
The phenomenon represents a reversible shift in allele frequencies rather than a permanent macroevolutionary speciation event.
- B.
The rapid phenotypic shift in the population during industrialization was an expression of phenotypic plasticity induced by the soot-heavy environment.
- C.
The resurgence of the non-melanic form post-industrialization confirms that the alleles for light wing color were never completely eliminated from the gene pool.
- D.
The initial increase in the melanic population illustrates directional selection driven by differential predation by birds.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Biston_betularia|Natural_Selection|Phenotypic_Plasticity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between population-level genetic shifts (Natural Selection) and individual-level non-heritable changes (Phenotypic Plasticity).
The trap exploits the Lamarckian misconception that the environment directly alters an organism's phenotype to suit its surroundings.
It also tests the NCERT nuance that directional selection does not necessarily mean the permanent extinction of the disadvantaged allele, highlighting the reversible nature of evolutionary chronology when selective pressures invert.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Evolution - Class 12 |
| Concept | Evolutionary Chronology |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |