Shirt that Eric Harris wore during the columbine massacre.
Natural selection. Eric wanted to shape the world to his liking, he often mentions ethnic cleansing and annihilation of 'stupid people' in his journal. Whereas Dylan Klebold's shirt implies an unleashed energy, Eric's implies a cold scientific determinism. Eric is simply enacting his natural right, by this measure, to mow down his classmates. Why? Because they are the "retards, people with brain fuck ups, drug addicts," and, most grievously of all, the "people who can’t figure out how to use a fucking lighter." They are the vapid sheep who have plagued his life, not just by their actions against him, but just by sheer virtue of their placid ignorance. "Natural Selection" is the "natural" order of things, after all.