The evolution of cellular computing: nature's solution to a computational problem

How do cells and nature 'compute'? They read and 'rewrite' DNA all the time , by processes that modify sequences at the DNA or RNA level. In 1994, Adle man's elegant solution to a seven-city directed Hamiltonian path problem us ing DNA launched the new held of DNA computing, which in a few years has gr own to international scope. However, unknown to this field, two ciliated pr otozoans of the genus Oxytricha had solved a potentially harder problem usi ng DNA several million years earlier. The solution to this problem, which o ccurs during the process of gene unscrambling, represents one of nature's i ngenious solutions to the problem of the creation of genes. RNA editing, wh ich can also be viewed as a computational process, offers a second algorith m for the construction of functional genes from encrypted pieces of the gen ome. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.