Answer:
D. an overarching explanation, supproted by much evidence, for how populations change over time.
Explanation:
Evolution is defined as the change of specific characteristics of a species over time or over several generations and it mainly relies on natural selection phenomenon.
Basically, evolution is an idea which is based on this fact that all species are gradually change with the passage of time.
In biology, evolution is defined as the change of specific heritable characteristics over successive generations. Means, that the particular expression of genes having characteristics transfers from parents to offsprings and over the generation there can be mutation occurs in genes and the particular characteristics can lead to change in next generation.
So, evolution is the phenomenon which change the characteristics over the time.