Are we all descendents of Noah (Nuh AS)?

When I heard the story of prophet Nuh (AS) I always assumed it was only him and his sons left in the whole entire world, but recently I've heard theories that only Nuh's tribe was drowned and other parts of world consisted of other people. Assuming only him and his sons were left, we would all be descendants of Nuh. But is it possible that there were other people existing in other parts of the world? does the Quran ever explicitly say that only prophet Nuh and his sons stayed alive?