A new way to think about hitch hiking, called Panspermia or the concept of life spreading across different planets and galaxies. Microscopic organisms hitching a ride on an asteroid or intelligent beings plot a course for new horizons. Mathematically, both of those situations would show the same basic pattern.  Think of it similar in concept of simultaneous evolution which happened to our planet on different continents, across oceans.

http://www.space.com/30412-life-spreads-across-universe-epidemic.html