Scientists expand DNA's genetic alphabet from 4 to 8 letters using bacterial enzyme

For billions of years, every living thing on Earth has spoken the same four-letter genetic language — a constraint so ancient it seemed indistinguishable from natural law. Researchers at UC San Diego have now demonstrated that this is not a boundary but a starting point: a bacterial enzyme successfully read an expanded eight-letter DNA alphabet, called hachimoji, with the same fidelity it brings to ordinary life. The machinery of life, it turns out, is more flexible than evolution required it to be, and that flexibility may open corridors into forms of biology that natural selection never walk