Ubiquity, an ACM publication February, ʹͲͳͳ http://ubiquity.acm.org ͳ ©ʹͲͳͳ Association for Computing Machinery Ubiquity Symposium What is Computation? Biological Computation by Melanie Mitchell Computer Science Department, Portland State University and Santa Fe Institute Editor’s Introduction In this thirteenth piece to the Ubiquity symposium discussing ‘What is computation? ’ Melanie Mitchell discusses the idea that biological computation is a process that occurs in nature, not merely in computer simulations of nature. Peter J. Denning Editor