This is a drawing I did for a 3dtotal.com speed-painting challenge last year.
It was directly influenced by my experience of watching Metropolis, the 1927 classic movie by Fritz Lang. One thing I find very fascinating in particular was their choice of strange but fully plausible words for things we commonly know by different names today; e.g. the robot in the movie wasn't called robot but Maschinenmensch (Machine Man).
The Picture's Concept
Once upon a time, humankind was extinguished, the Maschinenmenschen took over the Earth and started to live by themselves; developing their neural networks slowly reaching a state where they were intelligent enough to realize their own existence and roots...
Artists' Very Short Explanation
Their roots are the humans who created them initially. Humankind is represented by the human skull it's quite a bit like in Hamlet maybe; or maybe not. I don't know really.
The title of the picture is the german word for "existence"; but that probably wasn't hard to guess.