Answer:
O C. Small changes add up over many generations.
Explanation:
Evolution by natural selection states that small changes (different allele frequencies) that confer upon an individual a reproductive advantage will eventually cause the <em>population</em> to evolve into something different. The accumulation of all these little changes as alleles become more frequent will eventually cause evolution.
Why not A: Not all animals need to reproduce. This is the opposite of what's true: only some animals live long enough to reproduce and increase the frequency of their alleles in the population.
Why not B: They have to be passed down. Remember, these adaptations are not acquired, like Lamarck thought, but rather inherent in genetics, as Darwin thought.
Why not D: This is just plain wrong.
