\begin{thebibliography}{10}

\bibitem{adami94}
{\sc Adami{\rm , C.}, {\rm and} {\rm C.~T. }Brown},
\newblock ``Evolutionary learning in the {2D} artificial life system
  ``{Avida}'''',
\newblock {\em Artificial Life IV: Proceedings of the Fourth International
  Workshop on the Synthesis and Simulation of Living Systems\/} (Cambridge,
  Massa\-chu\-setts, ) ({\sc R.~Brooks and P.~Maes} eds.),
\newblock MIT Press (July 1994),
\newblock 377--381.

\bibitem{byl89}
{\sc Byl{\rm , J.}},
\newblock ``Self-reproduction in small cellular automata'',
\newblock {\em Physica D {\bf34}\/} (1989),
\newblock 295--299.

\bibitem{chou97}
{\sc Chou{\rm , H.~H.}, {\rm and} {\rm J.~A. }Reggia},
\newblock ``Emergence of self-replicating structures in a cellular automata
  space'',
\newblock {\em Physica D {\bf110}\/} (1997),
\newblock 252--276.

\bibitem{chou98}
{\sc Chou{\rm , H.~H.}, {\rm and} {\rm J.~A. }Reggia},
\newblock ``Problem solving during artificial selection of self-repli\-cating
  loops'',
\newblock {\em Physica D {\bf115}\/} (1998),
\newblock 293--312.

\bibitem{dewdney84}
{\sc Dewdney{\rm , A.~K.}},
\newblock ``In the game called {Core War} hostile programs engage in a battle
  of bits'',
\newblock {\em Scientific American {\bf250}}, 5 (1984),
\newblock 15--19.

\bibitem{langton84}
{\sc Langton{\rm , C.~G.}},
\newblock ``Self-reproduction in cellular automata'',
\newblock {\em Physica D {\bf10}\/} (1984),
\newblock 135--144.

\bibitem{pargellis96}
{\sc Pargellis{\rm , A.~N.}},
\newblock ``The evolution of self-replicating computer organisms'',
\newblock {\em Physica D {\bf98}\/} (1996),
\newblock 111--127.

\bibitem{perrier96}
{\sc Perrier{\rm , J.~Y.}, {\rm M.~}Sipper, {\rm and} {\rm J.~}Zahnd},
\newblock ``Toward a viable, self-reproducing universal computer'',
\newblock {\em Physica D {\bf97}\/} (1996),
\newblock 335--352.

\bibitem{ray90}
{\sc Ray{\rm , T.~S.}},
\newblock ``An approach to the synthesis of life'',
\newblock {\em Artificial Life II: Proceedings of the Workshop on Artificial
  Life\/} (Santa Fe, New Mexico, ) ({\sc C.~G. Langton, C.~Taylor, J.~D.
  Farmer, and S.~Rasmussen} eds.),
\newblock vol.~X of {\em SFI Studies in the Sciences of Complexity},
\newblock Addison-Wesley (February 1990),
\newblock 371--408.

\bibitem{reggia93}
{\sc Reggia{\rm , J.~A.}, {\rm S.~L. }Armentrout, {\rm H.~H. }Chou, {\rm and}
  {\rm Y.~}Peng},
\newblock ``Simple systems that exhibit self-directed replication'',
\newblock {\em Science {\bf259}\/} (1993),
\newblock 1282--1287.

\bibitem{sayama98phd}
{\sc Sayama{\rm , H.}},
\newblock {\em Constructing evolutionary systems on a simple deterministic
  cellular automata space},
\newblock {Ph.D.} dissertation Department of Information Science, Graduate
  School of Science, University of Tokyo (December 1998).

\bibitem{sayama98}
{\sc Sayama{\rm , H.}},
\newblock ``Introduction of structural dissolution into {Langton's}
  self-reproducing loop'',
\newblock {\em Artificial Life VI: Proceedings of the Sixth International
  Conference on Artificial Life\/} (Los Angeles, California, ) ({\sc C.~Adami,
  R.~K. Belew, H.~Kitano, and C.~E. Taylor} eds.),
\newblock MIT Press (June 1998),
\newblock 114--122.

\bibitem{sayama99alj}
{\sc Sayama{\rm , H.}},
\newblock ``A new structurally dissolvable self-reproducing loop evolving in a
  simple cellular automata space'',
\newblock {\em Artificial Life {\bf5}}, 4 (1999),
\newblock 343--365.

\bibitem{sipper94}
{\sc Sipper{\rm , M.}},
\newblock ``Non-uniform cellular automata: Evolution in rule space and
  formation of complex structures'',
\newblock {\em Artificial Life IV: Proceedings of the Fourth International
  Workshop on the Synthesis and Simulation of Living Systems\/} (Cambridge,
  Massa\-chu\-setts, ) ({\sc R.~Brooks and P.~Maes} eds.),
\newblock MIT Press (July 1994),
\newblock 394--399.

\bibitem{tempesti95}
{\sc Tempesti{\rm , G.}},
\newblock ``A new self-reproducing cellular automaton capable of construction
  and computation'',
\newblock {\em Advances in Artificial Life: Proceedings of the Third European
  Conference on Artificial Life (ECAL'95)\/} (Granada, Spain, ) ({\sc
  F.~Mor\'an, A.~Moreno, J.~J. Merelo, and P.~Chac\'on} eds.),
\newblock vol.~929, Lecture Notes in Artificial Intelligence of {\em Lecture
  Notes in Computer Science},
\newblock Springer-Verlag (June 1995),
\newblock 555--563.

\end{thebibliography}