Test: Mechanism of Evolution - NEET MCQ

• Hugo de Vries proved mutation theory by doing experiments on Oenothera lamarckian, also known as evening primrose.
• It was from this plant; he came up with the observations.
• It is a complex heterozygous plant with a chromosomal aberration.

Line in NCERT: "In the first decade of twentieth century, Hugo deVries based on his work on evening primrose brought forth the idea of mutations - large difference arising suddenly in that differ from other breeds."

• Single-step that causes large mutation is called saltation.
• It is called as such because the mutation occurs suddenly and abruptly that leads to evolution in large scale.
• Hugo de Vries used this term against Darwin’s theory of evolution.

Line in NCERT: "Hugo deVries believed mutation caused speciation and hence called it saltation (single step large mutation)."

Hugo de Vries's research on evening primrose led him to propose that mutations are a key factor in evolution, contrasting with Darwin's emphasis on gradual changes.

This highlights the fundamental difference in their theories, where Darwin's gradualism contrasts with de Vries's saltationism.