A Computer Program That Taught Itself to Draw the Mona Lisa

These images represent four steps in one computer program's progress
towards recreating the Mona Lisa using only 50 semi-transparent
polygons. Swedish programmer Roger Alsing did this simple weekend
project with genetic programming that resulted in a program that could
generate, on its own, a pretty awesome likeness of the famous painting.
So how did he do it?

He wrote a program that would randomly place shapes on a black
background, and decide whether the abstract pattern looked more or less
like the famous painting. After almost a million tries, the program's
output had evolved to the point where Alsing had the image on the far
right.

http://io9.com/5106124/a-computer-program-that-taught-itself-to-draw-the-mona-lisa