Question

According to Hugo de Vries, the mechanism of evolution is

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

Answer 1

The Correct Option is D

The correct answer to the question is "Saltation." Let's explore why this is the case:

Hugo de Vries was a Dutch botanist and a proponent of the mutation theory of evolution. He proposed that new species are created through a process known as "saltation", which means a sudden and significant change, rather than through the slow process of natural selection. This concept is distinct from Darwin's theory that emphasized gradual changes occurring over a long period.

1. Minor mutations: This option refers to small genetic changes that happen gradually. In contrast, Hugo de Vries emphasized significant changes (saltations), not minor ones, as the mechanism of evolution.
2. Multiple step mutations: This suggests a series of progressive mutations. Hugo de Vries focused on large, single-step mutations, not multiple steps, which is contrary to this notion.
3. Phenotypic variations: While phenotypic variations are observable traits that can result from mutations, Hugo de Vries' theory specifically highlighted significant phenotypic changes due to saltations.
4. Saltation: This term aligns perfectly with de Vries’ hypothesis of evolution, which proposes that new species originate through large, abrupt genetic changes.

In summary, Hugo de Vries suggested that saltation, representing significant genetic leaps, rather than incremental changes, is the primary driver of evolution. This theory stands in contrast to Darwin's gradualism, emphasizing the role of major mutations in species evolution.