How genetic novelty arises is one of the most elusive questions within genetics and has implications across numerous and diverse fields. Although there are many possible answers, reading frame-shifts in protein-coding DNA are known to create dramatically different peptides and have the potential to enable large evolutionary steps. The radical nature of these mutations have led to the assumption that they do not often survive and are strongly selected against. Nevertheless, when they occur in a duplicated gene, many of the negative selective pressures are alleviated. In this thesis I use a conservative method which proves that this is a mechanism by which genetic material has been commonly introduced to the human genome. In addition, I determine the characteristics which human genes formed by this mechanism most commonly share and the roles they have played in human evolution. Finally, I discuss the effects of frameshifting and the cooption of frameshifted genes on human evolution and more broadly genomic adaptation across the tree of life.