Uracil Broke Down 7 Times Faster Than Thymine Under Early-Earth UV Light, Hinting at Why DNA Switched Letters
Nature World News | 16.10.2026 04:01
Under the kind of harsh ultraviolet light that bathed the young Earth, uracil, the genetic letter RNA uses, broke down about seven times faster than thymine, the letter DNA uses in its place. The result comes from a laboratory study by chemists at the University of Wisconsin-Madison, published in the Proceedings of the National Academy of Sciences.
