This pre-urban culture lead individuals to have a sense of individual freedom and autonomy. Many European cultures evolved from tribal confederations to larger states while retaining their sense of individual autonomy. The Romans and the Greeks all made this transition, and created entities that made citizens part of the governing class. The Germanic tribes did not make this transition except in England (and Iceland, as someone mentioned), where the groups that migrated in 400-700 AD from northern Germany brought with them their notions of individual liberty and self-governance at the local level. The English formed parliamentary institutions and created rights that survived the transition to monarchy, and survive to this day. The reason why the English democratic institutions survived, and Greek and Roman ones did not, is probably due to some peculiarities of the English situation that could have gone the other way very easily.
Point being that the notion of individual liberty was not invented by any culture, but came out of a certain type of socio-demographic milieu that was common to many peoples of Europe. That democratic government arose independently in some of these countries as they made the transition to statehood is not surprising. That it survived to the present in Britain is.
That said, Greek thought and institutions permeate western civilization in many, many ways. The conquests of Alexander the Great, and the spread of Greek culture over the entirety of the civilized world (the Hellenic world, if you will) is one of the events that impacts us to this day. Even nations never governed by the Roman/Greek world felt its influence indirectly, as the Germans and Scandinavians did when they became Christian.
I absolutely agree--the roots of representative government rose from the same cultural (or socio-economic) stimuli for the PLINES, the Greeks, and the Romans. For whatever reason, though, the variant arising from the PLINES (NOT just the British!!!, if you please!!!) survived the transition from tribal, through monarchy, and into the modern era. Why??? Maybe there is some reason that the other variants went the way of the dodo in their originating environments, and the north European variant did not.
But my basic point remains the same---we were all taught in our history and social studies classes that the British/US/Western European representative government model stems solely from Greek and Roman roots, completely ignoring the contributions to same made by the PLINES. This is erroneous.