Molecular computing: Does DNA compute?

The concise algorithm by which protein functions are encoded in DNA sequences, and the flexible and adaptable operating systems of biological organisms, have long been coveted by computer scientists. Similarly, the information storage capacity of computers and their extraordinary problem-solving speed have been the envy of biologists. The parallels between the two systems are many, and it would seem natural to try to combine them. Indeed, computer scientists have been quick to take advantage of many of the information-handling paradigms that have been tried and adopted by evolution. Neural nets, genetic algorithms and cellular automata all attempt to reproduce the elegance of biological systems in silicon. But despite the fact that the binary logic of machine code is superficially similar to the quaternary logic of base-pairing, reproducing the speed of computers in carbon has until recently been unattainable.