In 2025, researchers discovered QT45 — a roughly 45-nucleotide RNA molecule capable of catalyzing its own replication without protein enzymes. A template strand guides the assembly of a complementary copy: A pairs with U, C pairs with G, free nucleotides click into place one by one. When the copy is complete, the strands separate, and both become templates. One becomes two, two become four — exponential growth from pure chemistry. This may be how life began.