Earth life is much older than that
Simple organisms on Earth go back to at least 3.8 billion
years ago:
http://www.resa.net/nasa/origins_life.htm
http://www.brookes.ac.uk/geology/rock.html
Even these "simple" life forms are already relatively complex,
which means there has to be even older and even simpler
creatures to which they evolved from.
Add this to the fact that life seems to have appeared
shortly after Earth's formation and the last major
bombardment period, and it is a very good sign that
life at the basic level at least is common throughout
the Universe.