 The geographical spread of haplogroup N in Europe is well aligned with the Pit–Comb Ware culture, whose emergence is commonly dated c. 4200 BCE, and with the distribution of Uralic languages.Mitochondrial DNA studies of Sami people, haplogroup U5 are consistent with multiple migrations to Scandinavia from Volga-Ural region, starting 6,000 to 7,000 years before present.The relationship between roles of European and Asian colonists in the prehistory of Finland is a point of some contention, and some scholars insist that Finns are "predominantly Eastern European and made up of people who trekked north from the Ukrainian refuge during the Ice Age".