 Let us first consider a special case, the universality of the genetic code. In molecular biology, unlike in popular science articles, the term “genetic code” does not refer to an organism’s genomic DNA sequence but to the assignment of amino acids to base triplets on the messenger RNA. There are four such bases: A, U, G and C. Three bases together form a “codon” and specify an amino acid, for example, the triplet AUG specifies the amino acid methionine (it is also a start codon, i.e., it initiates an open reading frame for making a protein). It was remarkable to find that the genetic code is completely identical in almost every organism that has been studied so far. There are only a few exceptions known, for example, the genetic code of mitochondria and chloroplasts or that of Trypanosomes (a human parasite causing sleeping sickness). Therefore, the code is called “universal”, because the exceptions are so few. But how do biologists know that the code is universal, given that it has been determined only in a small number of species?