First some biology. What is life, anyway?

• Properties of life on Earth

  • Composed of Cells
    • Not necessarily a universal property of life
    • Some non-living things have cell like structures
  • Uses energy
    • Many things that are not life also use energy
  • Self Replicating
    • Based upon a stored pattern or template (DNA)
    • Some non-living chemicals can be considered to be self replicating.
  • Capable of responding to the environment.
    • There are non-living things that also respond to the environment.
  • Maintains homeostasis (internal balance)
    • Also present in some non-living things (i.e. climate on the Earth).
  • Capable of evolution due to imperfect replication.

Notes: