Synthetic biology

Abstract

Synthetic biology is a growing discipline that has two subfields. One uses unnatural molecules to reproduce emergent behaviors from natural biology, with the goal of creating artificial life. The other seeks interchangeable parts from natural biology to assemble into systems that act unnaturally. Either way, a synthetic goal forces scientists to cross uncharted ground to encounter and solve problems that are not easily encountered through analytical methods. This drives the emergence of new paradigms in ways that analysis cannot easily do. The common goal for both subfields is the use of interchangeable parts to develop new systems to meet performance specifications. These parts must function (to a first approximation) independently. Obtaining interchangeable parts is easier in the macroscopic world than in the molecular world; the principal challenge in synthetic biology is to identify interchangeable parts in the molecular world. The development of living chemical systems and novel organisms allows the scientific community to better understand how the individual chemicals and genes involved in biology interact to form new emergent properties. Synthetic biologists have developed artificial genetic systems that can undergo Darwinian evolution. This has provided insight into the chemical constraints that need to be met by a genetic system. Synthetic biologists have also developed 'toy' organisms and systems, such as an organism that functions as an oscillation system, and a molecular automaton that can interactively play tic-tac-toe with a human. Synthetic biology has used metabolic-pathway design and genetic elements to develop organisms that can synthesize important chemicals, such as precursors for antibiotics and polymers. Truly interchangeable parts at the molecular level have so far only been obtained with nucleic acids. Using amino acids and the secondary structural elements of proteins as interchangeable parts has not yet been possible. Interchangeable genetic elements are possible, although their use is not without complications. Artificial chemical systems that support Darwinian evolution — the bridge between non-life and life — are allowing synthetic biologists to realize the relationship between life and chemistry. The hazards of synthetic biology are open for discussion, because the ability to develop living systems and organisms with novel functions could conceivably be used maliciously.