A group of scientists has created an organism that produces an amino acid that no other living thing has ever used.

All living things use the same 20 amino acids to build all of the proteins that make up all living cells. Now, scientists led by Scripps Research Institute chemistry professor Dr. Peter Schultz have engineered a version of the E. coli bacteria that can produce a 21st amino acid.

The project is designed to help answer some of the basic questions regarding the evolution of life, such as why organisms have not evolved more than 20 of these basic chemical building blocks. The researchers hope to learn whether access to additional amino acids could give organisms an evolutionary advantage.