High frequency of lactose intolerance in a prehistoric hunter-gatherer population
in northern Europe
The DNA of 10 Scandinavians from the Neolithic Pitted Ware Culture (ca 3200 BC– ca 2300 BC) was tested for the allele 13910 T/C associated with lactase persistence (CT and TT) or lactose intolerance (CC). Only one T allele was found out of 10 pairs, i.e. an incidence of 5%. This is very low compared to the present percentage of lactase persistence in the Swedish population (76% of T allele according to this study, but over 95% of actual lactose tolerance as only one allele is needed to be tolerant).
This means that the Scandinavians have changed a lot genetically over the last 4000 years, probably due to the arrival of the Indo-Europeans with the Corded Ware culture (mostly R1a) and later Bronze and Iron Age migrations from Central Europe (mostly R1b). Neolithic Scandinavians are thought to have belonged almost exclusively to Y-haplogroup I1.
The mutation for lactase persistence is believed to have originated in the Pontic steppes, probably between the Volga and the Urals, west of the Ural, between 4600 and 2800 BCE. The Indo-European expansion into Poland, Germany and Scandinavia started around 3100 BCE, but didn't reach Sweden before 2800 BCE. The single allele found in this study is likely a first trace of Indo-European admixture.
in northern Europe
The DNA of 10 Scandinavians from the Neolithic Pitted Ware Culture (ca 3200 BC– ca 2300 BC) was tested for the allele 13910 T/C associated with lactase persistence (CT and TT) or lactose intolerance (CC). Only one T allele was found out of 10 pairs, i.e. an incidence of 5%. This is very low compared to the present percentage of lactase persistence in the Swedish population (76% of T allele according to this study, but over 95% of actual lactose tolerance as only one allele is needed to be tolerant).
This means that the Scandinavians have changed a lot genetically over the last 4000 years, probably due to the arrival of the Indo-Europeans with the Corded Ware culture (mostly R1a) and later Bronze and Iron Age migrations from Central Europe (mostly R1b). Neolithic Scandinavians are thought to have belonged almost exclusively to Y-haplogroup I1.
The mutation for lactase persistence is believed to have originated in the Pontic steppes, probably between the Volga and the Urals, west of the Ural, between 4600 and 2800 BCE. The Indo-European expansion into Poland, Germany and Scandinavia started around 3100 BCE, but didn't reach Sweden before 2800 BCE. The single allele found in this study is likely a first trace of Indo-European admixture.