I really want to know. So far, only Greece has a well enough recorded history to document events; however, Rome is an open slate. Rome seems more intriguing because their government seemed to overlap over Greece's Republic, yet with little documentation leading up to it's creation.
Kinda depends how you want to define representation. I'm sure to some degree you could find it sprouting up all over the world.
The thing about representation is that when you speak of Rome, the politicians weren't really elected to speak for the people. They ran not on political messages or promises but on ancestral reputation and their own past deeds. This is why you don't have parties or anything in Roman politics, it's basically everyone scrambling for the top. So even though Rome had overlap with Greece, those elected wouldn't necessarily represent the people who elected them.