 In this section, four distinct questions have been described that appear under the rubric of “the units of selection” problem, What is the interactor? What is the replicator? What is the beneficiary? And what entity manifests any adaptations resulting from evolution by selection? There is a serious ambiguity in the meaning of “adaptation”; which meaning is in play has had deep consequences for both the group selection debates and the species selection debates (Lloyd 2001). Commenting on this analysis, John Maynard Smith wrote in Evolution: 