For several years the prevailing theory was that during the Last Glacial Maximum (LGM) ^[1] the I1 group sought refuge in the Balkans. ^[2]  For a time, the Ukraine was considered as an alternative.  Yet, The Genographic Project claims that the founder of the I1 branch lived on the Iberian Peninsula during the LGM. Some have given southern France and the Italian peninsula as possible sites as well. ^[3]  Although the locations vary, proponents of the refuge theories do seem to agree on one issue: that the I1 subclade is from 15,000 to 20,000 years old. ^[4]

A map of European LGM refuges, including the Balkans, where some believe the ancestors of I1 lived.  Approximately 20,000 years ago, much of Europe was covered in ice and permafrost.  The theory has been challenged recently by an opposing argument that I1 was not in existence during the LGM.

However, professor Ken Nordtvedt of Montana State University believes that I1 is a more recent group, probably emerging after the LGM. ^[5]  Other researchers including Peter A. Underhill of the Human Population Genetics Laboratory at Stanford University have since confirmed this hypothesis in independent research. ^{[6] [7]}  The map below showing the expansion of the Germanic tribes from 750 BC to AD 1 also appears to support this concept.

The study of I1, which some had argued was largely ignored by the genetic testing industry in favor of "mega-haplogroups" like R, is in flux.  Revisions and updates to previous thinking, primarily published in academic journals, is constant, yet slow, showing an evolution in thought and scientific evidence. ^[8]

The expansion of the Germanic tribes 750 BC – AD 1 (after the Penguin Atlas of World History 1988):       Settlements before 750BC       New settlements until 500BC       New settlements until 250BC       New settlements until AD 1

The most recent common ancestor (MRCA) of I1 lived from 4,000 to 6,000 years ago somewhere in the far northern part of Europe, perhaps Denmark, according to Nordtvedt.  His descendants are primarily found among the Germanic populations of northern Europe and the bordering Uralic and Celtic populations, although even in traditionally Germanic demographics I1 is overshadowed by the more prevalent Haplogroup R.

When SNPs are unknown or untested and when short tandem repeat (STR) results show eight allele repeats at DNA Y-chromosome Segment (DYS) 455, haplogroup I1 can be predicted correctly with a very high rate of accuracy, 99.3 to 99.8 percent, according to Whit Athey and Vince Vizachero. ^{[9] [10]}  This is nearly exclusive and ubiquitous to the I1 haplogroup, with very few having seven, nine or otherwise.  Furthermore, DYS 462 divides I1 geographically.  Nordtvedt considers 12 allele repeats to be more likely Anglo-Saxon and on the southern fringes of the I1 map while 13 signifies more northernly, Nordic origins. ^[11]  SNP testing is generally not as beneficial as expanded STR results, Nordtvedt has repeatedly argued, at least for I1.

The Great Migration in Europe or Völkerwanderung ("wandering of peoples") during the 1st century occurred in two stages.  The Germanic tribes were part of the first wave roughly from AD 300 to 500 during the decline of the Roman Empire.  It may have been triggered in part by Hun and Mongol incursions and Turk migrations in central Asia.  Later from about 800 to 1100 the three branches of Vikings — Danes, Swedes, and Norwegians — raided and settled large areas of eastern and western Europe, with remote outposts in Iceland and North America. ^[12]

In Russia Scandinavian invaders were known as Varangians. ^[13] Varangian leader Rurik founded the first Russian state.  Although recent genetic studies have identified two major royal lines, R1a and N1c1a, ^[14] genetic research shows significant I1 contribution centering on Moscow. ^[15]  John Haywood, author of The Great Migrations, believes that a group known as the Rus preceded the Varangians.

Goth movement into Poland, the Ukraine, the Crimea and later the Roman Empire also contributed to the dispersion of I1 throughout Europe and may explain its presence in the Balkans. ^[16]

Norsemen in the early medieval period who raided and plundered areas in Great Britain and Ireland were generally called Vikings.

This article found in Wikipedia. ^[17]

All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.)

References:

1. Introduction to the Ice Age
2. Map of LGM Haplogroup Refuges
3. Maps of Haplogroup I Subclades
4. Atlas of the Human Journey
5. RootsWeb: Discussion on Y-DNA-HAPLOGROUP-I Mailing List
6. New Phylogenetic Relationships for Y-chromosome Haplogroup I: Reappraising its Phylogeography and Prehistory
7. Nordtvedt Overview of New Phylogenetic Relationships for Y-chromosome Haplogroup I
8. No Consensus on Viking Influence
9. Y-Haplogroup Predictor
10. Allele Frequency Among I1a Samples
11. Signature Markers
12. Map of Viking Migrations and Settlements
13. Viking Description from The Columbia Encyclopedia, Sixth Edition
14. Vikings in Russia, Rurikid Dynasty DNA Project
15. Map of I1a in Russia
16. Gothic War in the Balkans
17. Haplogroup I1 (Y-DNA)