Thomas S. Ray (currently: Dept. of Zoology, Univ. of Oklahoma) Ecologist and
Ray had been introduced to self-replicating computger code in a virtual machine
(Core Wars) by an MIT hacker. Introduced feature of mutation by which code randomly
flipped bits when copying data; if that data happened to be machine code for
a program, the program mutated. Effects could rapidly be traced through many
generations. Beginning of work on Digital Evolution--Evolution by natural selection
embedded in "the medium of digital computation."
- Evolution by natural selection has generated complex and intelligent
life forms in the medium of carbon chemistry.
- Evolution is the only process with a proven ability to produce intelligence.
- The DNA of living organisms is a genetic ``program''. This is a parallel
software of a complexity much greater than any that could be written
- Experiments illustrated here show that evolution by natural selection
works very effectively in the medium of computer machine code.
- Evolution will find forms and processes that exploit the possibilities
inherent in the computational medium.
- Self-replicating machine code programs are introduced to the RAM memory
of the computer.
- Genetic variation occurs due to ``mutations'' resulting from random
flips (between 0 and 1) of bits in the memory.
- A ``reaper'' function of the operating system kills old or defective
processes in order to make way for newborn programs, once the memory
|Hosts, red, are very common. Parasites, yellow, have appeared
but are still rare.
||Immune hosts (blue) are increasing in frequency, separating
the parasites into the top of memory.
From: Tom Ray, "Tierra Photoessay," URL: http://www.isd.atr.co.jp/~ray/pubs/images/index.html