In a giant feat of genetic engineering, scientists have created bacteria that make proteins in a radically different way than all natural species do. By Carl Zimmer At the heart of all life is a code.

The genetic code is the recipe for life, and provides the instructions for how to make proteins, generally using just 20 amino acids. But certain groups of microbes have an expanded genetic code, in ...

"The genetic code is this amazing thing in which a string of DNA or RNA containing sequences of four nucleotides is translated into protein sequences using 20 different amino acids," said Joanna Masel ...