Any day now, or then again maybe two decades from now, scientists could announce that they have created life from scratch—essentially transforming inert chemicals into a life-form that can replicate itself and possibly even evolve. Would such a scientific feat alter your view of how life could have begun on Earth? Some people feel such a feat would “demystify” life in a troubling way; others would welcome it as an advance in scientific understanding.
Researchers talk about making artificial life in two ways—top-down and bottom-up. The bottom-up approach builds cells from nonliving components. The top-down method involves modifying cellular structures (often by simplifying the genetic material) to make the cell less complex and to identify its essence by stripping away unnecessary elements.
This NOVA scienceNOW documentary describes how scientists are trying to create tiny life-forms—converting nonlife into self-sustaining, living creatures. The program discusses the requirements for life: structure enclosing a space, such as a cell membrane or cell wall; the ability to grow or change using energy and giving off waste products; the ability to reproduce and pass traits to offspring; and for some, the ability to evolve. The documentary shows scientists combine the bases adenine, thymine, guanine, and cytosine to make DNA that self-assembles into a gene that codes for something specific, such as making bacteria glow green.
But making a creature from scratch that meets all four requirements is much, much harder than making a gene. In fact, no one has been able to do it. But now, scientists all over the world are working on different parts of this puzzle. But if and when we begin to make life, the question is, can we control it?