The game of Life?

http://en.wikipedia.org/wiki/Conway's_Game_of_Life

is it possible to do this in reverse? draw a pattern which follows those rules to find an initial set of the fewest cells and their locations that would wind up producing the drawn pattern?

another question: is it possible to determine the rules based on the way patterns form (for instance say one of the rules was left out, or another rule added, would analysis of the pattern formation tell you what the left out or added rule was?