Question

According to Hugo de Vries, the mechanism of evolution is

• A. Multiple step mutations
• B. Phenotypic variations
• C. Saltation
• D. Minor mutations

Answer 1

The Correct Option is C

The question asks about the mechanism of evolution according to Hugo de Vries. Let's explore what each of the provided options means in the context of evolutionary biology before identifying the correct answer.

1. Multiple step mutations: This refers to the hypothesis that evolution occurs through a series of small, gradual changes accumulated over time. However, this idea aligns more closely with Darwinian evolution rather than de Vries' views.
2. Phenotypic variations: These are observable traits that vary among individuals within a population due to genetic differences. While phenotypic variation is crucial for natural selection, it does not specifically highlight the mechanism proposed by de Vries.
3. Saltation: This is the concept proposed by Hugo de Vries where evolution occurs via sudden, large mutations, which he called "mutations" leading to new species or new traits. Saltation implies a jump rather than gradual changes, which aligns with de Vries' mutation theory of evolution.
4. Minor mutations: These involve small changes in the genetic material, contributing to gradual evolutionary change. However, minor mutations do not represent the sudden, large-scale changes indicated by de Vries through saltation.

Based on the definitions and theory proposed by Hugo de Vries:

• Saltation refers to the sudden occurrence of new traits due to significant mutations, differing from gradual evolutionary models. Therefore, this is the concept introduced by de Vries.

Conclusion: The correct answer is Saltation, as this was de Vries' proposed mechanism of evolution through sudden, large mutations.