All currently known life is based on three classes of molecules: proteins – life’s main structural and functional building blocks; DNA – life’s information molecule; and RNA – a molecule that provides the link between these two. But does future life have to be reliant on these molecules or could a living organism be made of e.g. steel, rubber, copper, and silicon? 

The book explores the fundamental connections between life and information and how they emerged inextricably linked, taking the reader on a journey through all the major evolutionary transitions. We do not know what the first carriers of information were when life had just emerged, but for the last few billions of years, the most important information storage medium on Earth has been DNA. Evolution processes the information recorded in the entire collection of DNA on Earth using the algorithm of Darwinian selection of the fittest. Once life had emerged and started evolving, the information in DNA was accumulating, at least for a while. One can say that evolution was learning from interactions with the environment, recording the useful bits of information in its genomes. A few hundred thousand years ago, quite recently on the evolutionary timescale, human language emerged and a major transition began; for the first time, large amounts of information began accumulating outside DNA. Moreover, language triggered evolutionary mechanisms different from and faster than biological evolution, namely cultural evolution; the emergence of human language was a transition as remarkable as the emergence of life itself. Nevertheless, at least at our current state of evolution, the information in DNA is indispensable; if the DNA existing on Earth were to become too corrupted, all cultural information and life itself would swiftly disappear. But must life be like this? Or can future civilizations, possibly in thousands or millions of years colonizing planets of distant galaxies, be based on entirely different principles? Can there be another major transition in which DNA becomes less central? And where will life go after the Solar system ceases to exist?