For 10 points, name these organisms that are not natural.
Mark A. Bedau edits a journal dedicated to these entities. Thomas Ray's Tierra project was an effort to  create these entities. One program for studying the long term behavior of these entities is Chris Adami's  Avida. Steen Rasmussen was inspired by Core Wars to create a primitive one of these entities. Langton coined this  term and proposed that they should be created using cellular automata. Markus Covert's recently published work on  Mycoplasma genitalium almost constitutes one of these. For 10 points, name these organisms that are not natural.
Mark A. Bedau edits a journal dedicated to these entities. Thomas Ray's Tierra project was an effort to  create these entities.
artificial life [or virtual organisms; or digital organisms; accept equivalents]