Who proposed the theory of evolution by natural selection

Step 1: Analyze the question The question asks who proposed the theory of evolution by natural selection. The key phrase is "natural selection."

Step 2: Explain the concept Natural selection is the process by which organisms with traits better suited to their environment survive, reproduce, and pass those traits to their offspring. Over many generations, the population changes. Its main points are:

• Organisms produce more offspring than can survive.
• There is variation among individuals.
• Individuals with favourable variations survive and reproduce more (survival of the fittest).
• Favourable traits are inherited and become more common over time.

Charles Darwin developed this theory and published it in On the Origin of Species (1859). Alfred Russel Wallace independently arrived at the same idea, but Darwin is the name credited in this question.

Step 3: Check each option

• A. Darwin: Correct. He proposed evolution by natural selection.
• B. Lamarck: Proposed the theory of use and disuse and the inheritance of acquired characteristics (for example, the giraffe stretching its neck). This is a different theory, and it was later discredited.
• C. Aristotle: An ancient Greek philosopher who classified living things and wrote on biology, but he did not propose natural selection.
• D. Linnaeus: Known as the father of taxonomy, who introduced binomial nomenclature (for example, Homo sapiens). He was not an evolution theorist.

Step 4: Answer The correct option is A. Darwin.

Exam tip: Pair each name with its key idea:

• Darwin = Developed natural selection
• Lamarck = Lack of use makes organs disappear, so acquired traits are inherited
• Linnaeus = Labelling (naming and classification)

Also note that "Lamark" in option B is a misspelling of Lamarck.