The science of biology celebrates the discovery and understanding of biological systems that already exist in nature. In parallel, the engineering of biology must learn how to make use of our understanding of the natural world to design and build new useful biological systems. ""Synthetic biology"" represents one example of recent work to engineer biological systems. This emerging field aims to replace the ad hoc process of assembling biological systems by primarily developing tools to assemble reliable-but-complex living organisms from standard components that can later be reused in new...