Which of the following statements explains the theory of natural selection?

Analyze the question: The question asks which statement explains Darwin's theory of natural selection.

Explain the concept: Darwin's theory of natural selection rests on these ideas:

1. Organisms produce more offspring than can survive.
2. There is a struggle for existence (competition for food, space, mates).
3. Individuals in a population show variation.
4. Those with favourable traits survive and reproduce, which is "survival of the fittest."
5. The less fit (weaker) individuals are eliminated, and favourable traits are passed to the next generation.

Evaluate the options:

• A. There is no struggle for existence. Wrong. Darwin said the struggle for existence is central to the theory.
• B. New species get better adaptation. This is a result, not the mechanism. It also suggests that adaptation is something organisms simply acquire, rather than the outcome of selection acting on variation.
• C. The weaker offspring are eliminated. This is the core of the mechanism: the environment "selects" and the less fit are removed, so the fitter survive and reproduce.
• D. Unused structures disappear later. This is Lamarck's theory of use and disuse, not natural selection.

Answer: The best statement is C.

Tip: Link the names to the ideas:

• Darwin = struggle for existence, variation, survival of the fittest, elimination of the weak.
• Lamarck = use and disuse, inheritance of acquired characters.

If an option mentions "use and disuse" or "acquired characters," think Lamarck and eliminate it.