Self awareness, a major component of consciousness is studied in brain-damaged patients. Self awareness comes from everywhere:-http://www.sciencedaily.com/releases/2012/08/120822181228.htm-And our wiring is much more complex compared to chimps and rhesus macaques:-http://www.sciencedaily.com/releases/2012/08/120822124708.htm-"Although all three species share a frontal cortex, our analysis shows that how the human brain regulates molecules and switches genes on and off unfolds in a richer, more elaborate fashion," -And all this developed by chance occurrances