Haplogroup U: Toward the Black Sea
Ancestral line: "Eve" > L1/L0 > L2 > L3 > N > R > U
Descending from the R group, a woman gave rise to people who now constitute haplogroup U. Because of the great genetic diversity found in haplogroup U, it is likely that this woman lived around 50,000 years ago.
Her descendants gave rise to several different subgroups, some of which exhibit very specific geographic homelands. The very old age of these subgroups has led to a wide distribution; today they harbor specific European, northern African, and Indian components, and are found in Arabia, the northern Caucasus Mountains, and throughout the Near East.
One interesting subgroup is U6, which branched off from haplogroup R while still in the Middle East, moved southward, and today is found in parts of northern Africa. Today, U6 individuals are found in around ten percent of people living in North Africa.
Other members of the larger haplogroup U descend from a group that moved northward out of the Near East. These women crossed the rugged Caucasus Mountains in southern Russia, and moved on to the steppes of the Black Sea. These individuals represent movements from the Black Sea steppes west into regions that comprise the present-day Baltic States and western Eurasia. This grassland then served as the home base for subsequent movements north and west. Today, members of these lineages are found in Europe and the eastern Mediterranean at frequencies of almost seven percent of the population.
While you do share distant ancestry with these subgroups of U, your genetic lineage went in a different direction.
Haplogroup U5: Your Branch on the Tree
Ancestral line: "Eve" > L1/L0 > L2 > L3 > N > R > U > U5
We finally arrive at your own clan, a group of individuals who descend from a woman in the U branch of the tree. Her descendants, and the most recent common ancestor for all U5 individuals, broke off from the rest of the group and headed north into Scandinavia. Even though U5 is descended from an ancestor in haplogroup U, it is also ancient, estimated to be around 50,000 years old.
U5 is quite restricted in its variation to Scandinavia, and particularly to Finland. This is likely the result of the significant geographical, linguistic, and cultural isolation of the Finnish populations, which would have restricted geographic distribution of this subgroup and kept it fairly isolated genetically. The Saami, reindeer hunters who follow the herds from Siberia to Scandinavia each season, have the U5 lineage at a very high frequency of around 50 percent, indicating that it may have been introduced during their movements into these northern territories.
The U5 lineage is found outside of Scandinavia, though at much lower frequencies and at lower genetic diversity. Interestingly, the U5 lineage found in the Saami has also been found in some North African Berber populations in Morocco, Senegal, and Algeria. Finding similar genetic lineages in populations living thousands of miles apart is certainly unexpected, and is likely the result of re-expansions that occurred after the last glacial maximum around 15,000 years ago. Humans who had been confined to narrow patches in southern Europe began to move outward again, recolonizing ancient territories and bringing new genetic lineages with them.
In addition to being present in some parts of North Africa, U5 individuals also live sporadically in the Near East at two percent—about one-fifth as frequent as in parts of Europe—and are completely absent from Arabia. Their distribution in the Near East is largely confined to surrounding populations, such as Turks, Kurds, Armenians, and Egyptians. Because these individuals contain lineages that first evolved in Europe, their presence in the Near East is the result of a back-migration of people who left northern Europe and headed south, as though retracing the migratory paths of their own ancestors.