The mutation theory of organic evolution was propounded by?

Analyze the question: It asks who proposed the mutation theory of evolution, which says new species can arise suddenly through large, sudden changes (mutations) in organisms, not only through slow, gradual change.

Explain the concept: Each scientist is linked to a different idea:

• Gregor Mendel: Father of genetics. He worked on inheritance in pea plants and gave the laws of segregation and independent assortment. He did not propose a theory of evolution.
• Hugo de Vries: A Dutch botanist. While studying the evening primrose (Oenothera lamarckiana), he saw sudden, large, inheritable variations. He called them "mutations" and proposed the Mutation Theory (around 1901).
• Jean Baptiste Lamarck: Proposed the theory of use and disuse and the inheritance of acquired characters, as with the giraffe's long neck.
• Charles Darwin: Proposed natural selection, or "survival of the fittest", in On the Origin of Species.

Solution: The theory is about sudden, heritable changes (mutations) producing new species. This was the work of Hugo de Vries, who observed it in the evening primrose.

Correct answer: B. Hugo de Vries

Tip: Link each name to a key word:

• Mendel → Mendel = Genetics (peas)
• De Vries → Mutation (evening primrose)
• Lamarck → Long neck / use and disuse (acquired traits)
• Darwin → Differential survival (natural selection)

This matching pattern appears often in JAMB, WASSCE and NECO Biology, so it is worth memorizing.