Question

how does evolution happen? its a process that only takes a few years to have an effect. it just works. it works overnight through rapid mutations. it happens by natural selection and takes millions of years to take effect.

Explanation:

Evolution is a biological process. According to the theory of evolution by natural selection proposed by Charles Darwin, organisms with traits that are advantageous for survival and reproduction in their environment are more likely to pass on their genes. This process occurs over long periods, typically millions of years, as small genetic changes accumulate. Options like "only takes a few years" or "works overnight" are incorrect because evolution is a slow - paced process. The option "It just works" is too vague. The correct understanding is based on the mechanism of natural selection which acts over extended time frames.

Answer:

It happens by natural selection and takes millions of years to take effect.