Phosphorus Essential for Human DNA -- Rare in our Solar System and May have been Non-Existent on Early Earth | Science News | Scoop.it
From www.dailygalaxy.com - March 23, 2012 3:39 PM

Over 13 billion years ago at least one of the domains of life may have begun in nebular clouds. If restricted to the Milky Way, which is 13.6 billion years old, the first chemical combinations would have had billions of years to become a self-replicating organism with a DNA genome long before the existence of Earth.