"Haplogroup I-M253, also known as I1...
...reaches its peak frequencies in Sweden (52 percent of males in Västra Götaland County) and western Finland (more than 50 percent in Satakunta province). In terms of national averages, I-M253 is found in 35–38 per cent of Swedish males, 32.8% of Danish males, about 31.5% of Norwegian males, and about 28% of Finnish males.
Haplogroup I-M253 is a primary branch of haplogroup I* (I-M170), which has been present in Europe since ancient times. The other primary branch of I* is I-M438, also known as I2.
All known living members descend from a common ancestor 6 times younger than the common ancestor with I2.
According to a study published in 2010, I-M253 originated between 3,170 and 5,000 years ago, in Chalcolithic Europe.
A new study in 2015 estimated the origin as between 3,470 and 5,070 years ago or between 3,180 and 3,760 years ago, using two different techniques.
In 2007, it was suggested that it initially dispersed from the area that is now Denmark. However, Prof. Dr. Kenneth Nordtvedt, Montana State University, regarding the MRCA, in 2009 wrote in a personal message: "We don't know where that man existed, but the greater lower Elbe basin seems like the heartland of I1".
Latest results (Sept. 2019) published by Y-Full suggest I1 (I-M253) was formed 27.500 ybp (95 CI: 29.800 ybp – 25.200 ybp) with TMRCA 4.600 ybp (95 CI: 5.200 ybp – 4.000 ybp).
A 2014 study in Hungary uncovered remains of two individuals from the Linear Pottery culture, one of whom was found to have carried the M253 SNP which defines Haplogroup I1. This culture is thought to have been present between 7,500 and 6,500 years ago.
I-M253 is found at its highest density in Northern Europe and other countries that experienced extensive migration from Northern Europe, either in the Migration Period, the Viking Age, or modern times. It is found in all places invaded by the Norse.
Haplogroup I databases