In other words, mutations occur randomly with respect to whether their effects are useful. Thus, beneficial DNA changes do not happen more often simply because an organism could benefit from them.

Why is mutation random and natural selection not?

The genetic variation that occurs in a population because of mutation is random — but selection acts on that variation in a very non-random way: genetic variants that aid survival and reproduction are much more likely to become common than variants that don't. Natural selection is NOT random!

Is mutation random or adaptive?

Evolutionary theory says mutations are blind and occur randomly. But in the phenomenon of adaptive mutation, cells can peek under the blindfold, increasing their mutation rate in response to stress.