The range of rates for different genetic types of mutations

To understand the potential role of mutation in evolution, it is important to understand the enormous range of rates for different types of mutations. If one ignores this, and thinks of “the mutation rate” as a single number, or if one divides mutation into point mutations with a characteristic rate, and other mutations that are ignored, one is going to miss out on how rates of mutation determine what kinds of changes are more or less common in evolution.  It would be like allowing a concept of fitness, then subverting its utility by distinguishing only two values, viable and inviable. [1]