The issue at hand is picking civilizations, not filling out empty plots on a world map, which, arguably, selecting anything from Africa or America would be doing. Who ever heard of the Zulus in school history classes for not to mention various indian tribes, in other connection than their extinction by the hand of other civilizations. Talking civilizations, they should be considered great contributors to world history, which for better or worse has been been centred in and around Mesopotamia. Besides that, including Canada is intriguing, and could ultimately win my approval. It is nice with some innovative suggestions, though the mark on world history is harder to find. My own far fetched suggestion would be that of the Huns. I know, their mark on history resembles that of the Mongols, but surely had impact on 'world' history with the upheavel they brought with them. Other than that; The Israelis and Turks.