Nils Aall Barricelli, (January 24, 1912 – January 27, 1993)
was a Norwegian-Italian psychologist and mathematician. He did early computer-assisted experiments in symbiogenesis and evolutionary algorithms, considered pioneering in artificial life research. In the 50s he thought about to write a chess program to test evolutionary theories, and implemented a program in collaboration with Alex Bell, who wrote a fast legal move generator, in the early 60s. In 1974, while he researched at the University of Oslo, he participated at the First World Computer Chess Championship in Stockholm with his own chess program Freedom .
In 1954 Professor Nils Barricelli was visiting Princeton University. The University was then a leader in the new field of computing mainly due to the presence of von Neumann and his development of the (amongst others) MANIAC machines.
In a discussion with Reuben Fine, the well-known Grandmaster and psychologist, Barricelli said that he intended to program a machine in order to beat Fine in chess. Professor Fine replied that he was sure the machine would play a poor game. Whereupon we asked von Neumann of his opinion. He agreed with Professor Fine on the grounds that the machine was not even capable of translating from a foreign language into a decent English. I think that was a poor argument, but that was anyhow his opinion.
In 1962 Barricelli arrived at Manchester University in order to use the Atlas computer, a machine with many new features and probably, at the time, the most powerful computer in the world. His intention was to write a chess program which would be used to study certain theories of evolution. I was at Manchester at the time having just finished a year of computer research. Having also just got married I had turned my attention to the mundane problems of earning a living and was told that a Dr. Barry Chelly was looking for someone to write a chess program for Atlas. My first job ever was to help write a list legal moves generator for any chess position on a machine which was barely operational.
Cooper and Kozdrowicki have remarked that chess will persist, for the problem is so exciting that once a programmer gets involved there is virtually no way he can be stopped. Personally I do not agree but I do remember that working with Barricelli was an interesting experience which definitely sold me on a career in computing although Manchester was an exciting place for computer users in almost any subject at the time.
The legal-move generator had to be as fast as possible because it would be used by symbio-organisms - numerical patterns in the machine which could reproduce and mutate - to test evolutionary theories. In order to survive and grow these organisms had to learn how to play chess; this was their test in their battle for survival.
Alex Bell explains Barricelli's Symbioorganisms : Barricelli devised the following extremely simple rules for sexual (symbiogenetic) reproduction. There are two integer arrays, this generation and next generation. The array this generation initially contains a random pattern of positive and negative integers. The following algorithm (expressed in Algol) is now executed:
integer array this generation, next generation [1 :512]; begin loop: for i : = 1 step 1 until 512 do begin n := j := this generation[i]; reproduce: if j = 0 then goto next i; k := modulo 512 of (i) plus: (j); if next generation[k] > 0 then goto mutation else next generation[k] := n; j := this generation[k]; goto reproduce; mutation: next i: end; copy next generation into this generation; print this generation; goto loop; end;
- Nils Barricelli (1954). Esempi numerici di processi di evoluzione, Methodos, pp. 45-68, 1954
- Nils Barricelli (1957). Symbiogenetic evolution processes realized by artificial methods. Methodos: 143–182.
- Nils Barricelli (1961). Numerical testing of evolution theories. Part I Theoretical introduction and basic tests. Department of Biology, Division of Molecular Biology, Vanderbilt University, Nashville, Tennessee, Acta Biotheoretica, Springer Netherlands, ISSN: 0001-5342
- Nils Barricelli (1963). Numerical testing of evolution theories. Part II preliminary tests of performance. symbiogenesis and terrestrial life. Department of Biology, Division of Molecular Biology, Vanderbilt University, Nashville, Tennessee, Acta Biotheoretica, Springer Netherlands, ISSN: 0001-5342
- George Dyson (1997, 2012). Darwin Among The Machines: The Evolution Of Global Intelligence. Basic Books, Second Edition 2012, from amazon 
- David B. Fogel (2006). Nils Barricelli - artificial life, coevolution, self-adaptation . IEEE Computational Intelligence Magazine, Vol. 1, No. 1
- Alexander R. Galloway (2008). Creative Evolution. Cabinet, No. 42 Forgetting, pdf
- Alexander R. Galloway (2012). The Computational Image of Organization: Nils Aall Barricelli. Grey Room, No. 46 
- Nils Aall Barricelli from Wikipedia
- Nils Barricelli's ICGA Tournaments
- Luz e Sangue - Nils Aall Barricelli (1912–1993) with Image
- Darwin Among The Machines; or, the Origins of [Artificial Life]. a presentation by George Dyson, Edge 21, July 8, 1997
- A Universe of Self-Replicating Code by George Dyson, Edge.org, March 26, 2012
- Nils Barricelli’s 5 Kilobyte Symbiogenesis simulations and ‘molecule shaped numbers’ – A precursor to DNA Computing, Dataisnature, June 06, 2012
- Meet the Father of Digital Life by Robert Hackett, Nautilus, June 12, 2014
- George Dyson - The Birth of the Computer,  YouTube Video
- George Dyson Early experiments in digital evolution. From the column Retrospect by George Dyson
- Nils Barricelli's ICGA Tournaments
- Alex Bell (1978). MASTER at IFIPS. Excerpt from: The Machine Plays Chess? from Atlas Computer Laboratory, hosted by Rutherford Appleton Laboratory (RAL)
- Barricellian symbioorganisms in Alex Bell (1972). Games Playing with Computers. Allen & Unwin, ISBN-13: 978-0080212227, hosted by Rutherford Appleton Laboratory (RAL)
- Darwin among the Machines - Wikipedia
- Barricelli: Built with Processing by Alexander R. Galloway
- Leviathan by Thomas Hobbes