Duplications play a major role in shaping the genome. Duplication may range from extension of short tandem repeats, to duplication of a cluster of genes, and all the way to duplication of entire chromosomes or even entire genomes. Such duplications are probably fundamental to the creation of genetic novelty.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): What role does genetic novelty play in the genome?
unanswerable