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Next: A Digital Analog

Category: Artificial Life

Selecting Naturally for Differentiation

Thomas S. Ray
ATR Human Information Processing Research Laboratories
2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto, 619-02, Japan
Tel: 81-774-95-1063
Fax: 81-774-95-1008


A progress report on an effort to create conditions under which natural selection will favor cell differentiation in multi-threaded self-replicating machine code programs. ``Cell differentiation'' means that different threads of the process execute different code. The machine code algorithms exist in a networked environment in which they are able to move from machine to machine. They have a mechanism of sensing conditions on any participating machine of the network. This sensory data provides information on the CPU speed (in virtual machine instructions per second) and the number of competing processes (among other things) on each machine. The sensory data can be used to support a strategy for foraging for CPU cycles on the network. In this environment, natural selection might maintain or improve differentiated multi-threaded network navigation algorithms.

On Earth, evolution by natural selection in the organic medium has caused replicators to undergo a phenomenal increase in complexity. The fossil record indicates that this increase in complexity did not occur gradually, but rather that the bulk of the increase occurred in a small number of major transitions [3]. These major transitions included: origin of chromosomes, origin of eukaryotes, origin of sex, origin of multi-cellular organisms, origin of social groups.

Of these major transitions, perhaps the most dramatic, and best known, was the rapid origin and diversification of large multi-cellular organisms from micro-scopic single celled ancestors, in what has come to be known as the Cambrian explosion of diversity [1,2]. It has understandably been called evolution's ``big bang'', when there was a dramatic inflation of complexity of organisms, and species diversified rapidly into an ecological void.

next up previous
Next: A Digital Analog

Thomas S.Ray
Tue Jan 14 16:09:05 JST 1997