The evolution of cellular computing: natures solution to a computational problem

How do cells and nature `computeʹ? They read and `rewriteʹ DNA all the time, by processes that modify sequences at the DNA or RNA level. In 1994, Adlemanʹs elegant solution to a seven-city directed Hamiltonian path problem using DNA launched the new field of DNA computing, which in a few years has grown to international scope. However, unknown to this field, two ciliated protozoans of the genus Oxytricha had solved a potentially harder problem using DNA several million years earlier. The solution to this problem, which occurs during the process of gene unscrambling, represents one of natureʹs ingenious solutions to the problem of the creation of genes. RNA editing, which can also be viewed as a computational process, offers a second algorithm for the construction of functional genes from encrypted pieces of the genome.