Despite awe-inspiring diversity, nearly every lifeform—from bacteria to blue whales—shares the same genetic code. How and when this code came about has been the subject of much scientific controversy.

This circular diagram represents the genetic code, showing how the four nucleotide bases of RNA (adenine [A], cytosine [C], guanine [G], and uracil [U]) form codons that specify amino acids. Each ...

For example, one of the cornerstones of conventional views of genetic code evolution rests on the famous Urey-Miller experiment of 1952, which attempted to simulate the conditions on early Earth that ...