摘要: Lake Tanganiyka has lefty and righty cichlid fish that show there can be natural selection for a trait over its mirror image counterpart.This raises the question ‘Can biological of whole organism counterpart?’ That is, could fitness altered by simply changing it into own enantaniomorph? My answer is no. I present Flatlander thought experiment to demonstrate imagecounterparts are duplicates because they only differ in how happen oriented space. The counterparts have same intrinsic properties environment,so no difference fitness.