In the future a Laboratory was created to study genetics and genetic therapy. Scientists doing deep sea diving could potentially get genetics to be better. Athletes could better genetics for larger muscles or something, and prostitutes could get genetics for bigger breasts. However first things first, they need to actually evolve some people and figure out which genetics is the best for certain situations.
Not having a lot of money, and short on job opportunities you have become a test subject for the Lab. It was a nice job considering your genetics are going to be continually manipulated. However you get a good wage, a place to live while they do the experiments, and get good insurance and medical treatments for the rest of your genetically manipulated life.
Arriving at the lab you were greeted and explained how the evolution worked. Basically you would be doing an activity, and then a machine would take your genetics and manipulate them a bit. After computing millions of potential manipulations it would select the one that would increase your performance. Each of the mutations would be fairly small, but there are thousands of mutations in a session producing significant changes. Who exactly are you though?