Endemic

An object is said to be endemic to a rule if it can only exist in that rule, i.e. if no change in the rule's birth and survival conditions supports the object. The term is understood to be relative to a certain class of cellular automata, e.g. outer-totalistic Life-like cellular automata or isotropic non-totalistic cellular automata.

The only rule in which isotropically-endemic still lifes can exist is the identity function (namely B/S012345678), and such patterns' evolution in one iteration uniquely determines the rule being simulated. The smallest such pattern known is 77 cells.

See also

• Polyglot
• Outer-totalistically endemic patterns (category)
• Isotropically endemic patterns (category)

External links

• Endemic periodic patterns and still lifes (discussion thread) at the ConwayLife.com forums