Haplogroup U4 History from 23andme.com
About 45,000 years ago, humans began moving from the Near East onto the vast plains of eastern Europe. Haplogroup U4 appears to have arisen shortly after this initial colonization, about 40,000 years ago. Not long afterward, the approaching Ice Age made most of northern Eurasia uninhabitable, and all but a few small groups of humans were pushed southward into the less frigid regions. During the early stages of the Ice Age, U4 was mostly restricted to southeastern Europe and the Caucasus Mountains. However, as the glaciers receded and temperatures warmed, U4 began to expand. Its expansions soon spawned four daughter branches: U4a, U4b, U4c and U4d.
Today, U4 is most common among northwestern Siberian populations, reaching levels as high as 25% in the Krasnoyarsk Krai region of central Siberia. It can also be found at lower levels, around 5-10%, among the Mari, Mordvin, and Mansi people of the Volga-Ural region of western Russia as well as the Estonians and Finns who surround the Baltic Sea of Europe. In both these regions, people speak related languages belonging to the Finno-Ugric family. As the ancestors of these present-day Finno-Ugric speakers expanded westward from the Ural Mountains across the northern forests of Europe they carried with them the U4 haplogroup, which was gradually enveloped into other European populations along the Baltic and Atlantic coasts such as the Swedish, French, and Cornish.Haplogroup U4a
Unlike haplogroups U4c and U4d, which are comparably rare, U4a is found throughout northern Eurasia. It diverged from its U4 sister lineages about 21,000 years ago in the region surrounding the Baltic Sea. Today it is most common among the people of the Volga River and Ural Mountains of Russia, such as the Chuvash, Kets and Mari. It is also common among the Baltic and Finnish people of northern Europe who speak languages related to the Finno-Ugric tongues of the Volga-Ural region in western Russia.
The Finno-Ugric speakers surrounding the Baltic Sea and the northwestern Siberian groups both probably originated in the same spot, just north of the Black Sea. The spread of some branches of U4a can be tied to the spread of the Corded Ware, or "Battle Axe" culture that permeated much of Europe about 5,000 years ago, stretching from the Rhine River in the west to the Volga River in the east. Today, U4a is also present at low levels in western European populations, but the expansion farther west is clearly younger than the northward expansion. The expansion of people carrying U4a into western Europe is probably a consequence of the glacial retreat after the Last Ice Age, when many areas that had been covered in ice or otherwise uninhabitable began to show signs of life. U4a in European populations outside of the Baltic area is only about 12,000 years old.
Haplogroup of Conquerors
Recent research suggests that on two occasions during ancient times, conquering armies carried haplogroup U4 to new parts of the world. In Hungary, the haplogroup has been found at levels of 18% in DNA isolated from the 10th and 11th century tombs of Magyar conquerors who invaded the country around the turn of the 10th century.
Yet U4 was nonexistent in the graves of commoners who were buried at that time, and it is present at levels of only about 4% among Hungarians today. That pattern suggests that the Magyars, who introduced their language to Hungary, were never very numerous in spite of their cultural influence. It also helps explain why Hungarians have a language that is distinct from other eastern European tongues, even though they are fairly similar to their neighbors genetically.
The other case involving conquering armies and the U4 haplogroup is more mysterious. The Kalash are a small ethnic group of a few thousand people living in the three isolated mountain valleys on the border between Pakistan and Afghanistan. Distinct from their neighbors in culture, religion and appearance, they claim to be descendants of Alexander the Great, whose armies conquered the region during the 4th century BC.
While genetics can't be used to support that claim specifically, it does indicate a western Eurasian origin for the group. One out of three Kalash have mitochondrial DNA belonging to haplogroup U4, indicating an origin in the Near East or the Caucasus. In fact, every mitochondrial haplogroup found among the Kalash has its roots far to the west of their current homeland.