Humans popping up or wandering out?

The idea of all human life wandering out of Africa has always seemed a bit too convenient for me(not to mention politically correct). With the existance of fossil evidence from around the world showing that pockets of hominids existed, flourished & declined through-out history, can we not ume that Modern Humans stem from many sources, or did only the one 'African group' survive & evolve? A paper written a while back suggests that the idea a single African origen for Mankind was designed Post-world war 2 by Academics shocked by the destruction that the belief in superior races can bring. They believed that by 'proving' to the world our shared ancestry it would bring an end to bigotry - but this theory was pure fabrication. My personal opinion is that the idea of a single family of beings arising in East Africa & surviving against the odds(whilst all others failed) & conquered the world is far less believable than many numbers of Hominid groups originating across the planet.