33. Criteria for life: Applications to Exo- and Astrobiology

• Where did life originate, where did it evolve ? It must have developed rapidly during the precambrium on earth or it came from elsewhere.
• Searching for life on Mars: what are the facts which justify looking for it and the concepts to search for it ?
• Criteria for extraterrestrial life.
• Unique chemical signatures which identify life processes.
• Essential molecular components of living systems.
• How old is the genetic code ?
• Criteria for life and survival which determine the spreading of microorganisms on earth.