There is no single set of criteria, though a common definition is an entity that can grow, metabolize, respond to stimuli and reproduce. Of those characteristics, reproduction is the most vital for evolution; evolution cannot occur without reproduction.
I've been down this road with AndrewC. It's a dead end. the objective here is to lead you into a box and shut the door.
535 posted on 07/24/2006 11:56:49 AM PDT by js1138
(Well I say there are some things we don't want to know! Important things!")