In a 2009 paper Yu, Etheridge and Cuthbertson proposed a model that was intended to address two questions. The first was a question related to Muller's ratchet, "What ratio of mutations must be beneficial for the meanfitness of a population to increase in time?" The second question was related to the Hill-Robertson effect, "If many beneficial mutations are introduced into a population, how much will competition slow the rate of adaptation?" They introduced a model of an asexually reproducing population of fixed size N and mutation rate mu and conjectured that the rate of adaptation is O(logN/(log logN)^2) for large N so long as there is some positive ratio of beneficial mutations. I will present an outline of my proof of this conjecture.