The reward for these clever RNAs was the chance to make babies. Well, not exactly. RNAs can't reproduce like animals or plants, but given the right materials, they can make copies of themselves that are more or less identical. Subtle differences that may make an RNA better able to put carbon and nitrogen together - or render it completely useless, which is usually what happens. By selecting the RNAs that could speed alkylation and then letting them reproduce, generation after generation, Wilson eventually wound up with a group of RNAs that were really good at sticking the atoms together.
Natural evolution takes much longer, centuries and millennia rather than weeks and months.
But the process is the same, and Wilson's experiments provide the kind of support that RNA World detractors asked for. He's also trying to find RNAs that control other reactions and change them - like turning cancer genes off or growth hormone production on. Short of a time machine or records from alien observers, says Wilson, we'll never know exactly how life on earth began. Noller isn't so sure.