The genetic code is a table of codons that encode amino acids. It was discovered by two scientists at first and worked on by more within a decade or so after.

When Polyuridine, UUU, codon was used, the amino acid Phenylalanine was synthesised. Based on this observation, the speculated that each codon gives rise to one amino acid and thus did more experiments and came up with the genetic code where every codon except three encodes for a specific amino acids. The remaining three are called STOP codons because they bring amino acids synthesis to a halt as the tRNA moves along the mRNA. So that is how the genetic code was generated.

How was the genetic code originated?