In both A&E’s recent remake of The Andromeda Strain, and the 1971 version of the Micheal Crichton novel, scientists are confronted with a microscopic invader, Andromeda, that has none of the trappings that we associated with life, but which is definitely alive. It grows, reproduces and evolves—all without the benefit of DNA, amino acids, water, or the complex carbon-based proteins that make all life as we know it tick. Instead, Andromeda appears to be crystalline in nature.
Is such a lifeform possible? To know the answer to that question would mean we would know the “laws of life,” the topic of a panel at the first World Science Festival in New York. On the panel were Steven Benner, Paul Davies, and Maggie Turnbull, who are all engaged in the search for those laws in their own way. Davies and Turnbull are astrobiologists, hoping to find answers in extraterrestrial life, either in our solar system or around another star. If we do find extra-terrestrial life, we can, as Davies put it, compare that life to our own and then start to figure out what’s really fundamental about life, and what are “frozen accidents” of evolution peculiar to life on Earth (such as having five fingers on each hand). Benner is taking a different tack, trying to find the ultimate limits on life by creating synthetic biological systems totally different from anything else on Earth, such as DNA with not just the four base pairs common to life on Earth (base pairs constitute the ‘alphabet’ in which an organism’s genetic code is written), but as many as twelve base pairs.
Happily for Andromeda Strain fans, with our current knowledge base, all of the scientists seemed perfectly fine with the notion of crystalline life forms, with Turnbell arguing that at the end of the day, there may be no sharp line that divides living, biological, systems from non-living, abiotic, systems, and Davies noted the hypothesis of Alexander Graham Cairns-Smith, which postulates that life got its start on Earth in the form of self-replicating clay crystals.
