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- An implementation of the "Wa-tor" world program described in
- A. K. Dewdney's column in Scientific American, Dec., 1984,
- pp. 14-22. Dewdney described a program built on arrays, but
- suggested that it might go faster if built on linked lists.
- This version was made by R. N. Wisan in Dec. 1984 using that
- linked lists method.
-
- If requested, this program makes a data file which can be printed out
- and the first 320 Chronons can be graphed
-
- Wa-Tor is a distant planet, discovered by A. K. Dewdney in
- the Scientific American in December of 1984. It is toroidal
- in form and entirely covered with a liquid, largely composed
- of an oxide of hydrogen. Its fauna consists of two species:
- a predator sufficiently comparable to the terrestrial shark
- to permit the use of that name, and a prey species which we
- may refer to as "fish". Both species are parthenogenic.
- The interest which this simple biosystem holds for us is due
- to the fact that the frequency with which the "sharks" must
- feed, the breeding rates, and even the initial numbers of
- the two species are entirely determinable by the observer.
- This makes the planet an excellent site for ecological ex-
- periment free of extraneous factors affecting species sur-
- vival.
-
- The behavior of the two species are as follows:
- The ocean in which the "sharks" and "fish" swim forms a rect-
- angular grid, and once every chronon, each organism moves one
- step along this grid, space permitting.
- "Fish" move at random if an unoccupied place is available.
- "Sharks" also move at random except that they will always
- move to catch a fish if one adjoins.
- At breeding age, "fish" divide, after the manner of amoeba,
- provided space is available.
- "Sharks" breed by calving. The calf emerges alongside its
- mother, fully fed. The mother, however, has sacrificed her
- chance to feed during that chronon. A calf will not enter
- it''s breeding cycle until it has fed at least once.
- "Sharks" must feed at regular intervals, the length of which
- varies with the observer''s choice. A "shark" will die if it
- fails to feed within the required time period.