Mutations play a pivotal role in evolution as they introduce genetic diversity within populations. These changes in the DNA sequence can lead to new traits in organisms, some of which might provide a selective advantage in changing environments. Over time, beneficial mutations can become prevalent in the gene pool through the process of natural selection, while harmful mutations may be weeded out. Thus, mutations serve as the raw material for evolutionary change, allowing species to adapt and evolve over generations, contributing to the biodiversity we see today.