NEET 2018 · BiologyPrevious Year Question
According to Hugo de Vries, the mechanism of evolution is
Answer: (B) Saltation. Answer: (B) Saltation.
- A.Phenotypic variations
- B.Saltation✓
- C.Multiple step mutations
- D.Minor mutations
Correct Answer
(B) Saltation
Solution & Explanation
Answer: (B) Saltation. Hugo de Vries, based on his work on evening primrose, proposed that evolution is driven by mutations – large differences arising suddenly in a population – rather than the minor heritable variations Darwin described. He believed a single large mutation could cause speciation, which he termed saltation. Thus de Vries' mechanism of evolution is saltation, not gradual phenotypic or minor variations. NCERT Reference: Ch 6 Evolution, p.119, lines 41–43: "deVries believed mutation caused speciation and hence called it saltation (single step large mutation)".
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