The history of life, represented on a clock to demonstrate relative scale.  Midnight represents the formation of the planet Earth, and 11:59:59PM represents the current day. Note that humans only arrive on the scene at 11:58:43PM…

The History of Life, as represented on a clock

Source: http://www.geology.wisc.edu/homepages/g100s2/public_html/history_of_life.htm