sentences:  In 2008, William R. Buckley published two configurations which are self-replicators within the original 29-state CA of von Neumann.Buckley claims that the crossing of signal within von Neumann 29-state cellular automata is not necessary to the construction of self-replicators.Buckley also points out that for the purposes of evolution, each replicator should return to its original configuration after replicating, in order to be capable (in theory) of making more than one copy.