Alien Civilizations - How Do the Odds Stack up?

A journal published by the International journal of Astrobiology puts the number of advanced and stable alien civilizations to be atleast 361 in our very own Milkyway. The simulation run by the publishing body relies on our current working knowledge of the stars and planetary systems as well as the accepted viability and ability of primitive life to evolve into an advanced and intelligent form. If it is also assumed that life can seed out from one planet to another through organic molecules etched into asteroids, the number jumps to around 40000 intelligent civilizations!