The main theories on Albanian origins all suppose a Paleo-Balkanic main origin, but they vary between attributing this origin to Illyrians, Thracians, Dacians, or another Paleo-Balkan people whose language was unattested; among those who support an Illyrian origin, there is a distinction between the theory of continuity from Illyrian times, and those proposing an in-migration of a different Illyrian population. These propositions are however not mutually exclusive. The Albanians are also one of Europe's populations with the highest number of common ancestors within their own ethnic group even though they share ancestors with other ethnic groups.