European mtDNA Haplogroups

mtDNA Haplogroups

MtDNA Haplogroups

All mtDNA haplogroups found in Europe descend from the

N group

, which is thought to represent one of the two initial migrations by modern humans out of Africa, some 60,000 to 80,000 years ago. Nowadays haplogroup N is only found at extremely low frequencies in various parts of Eurasia.

Chronological development of mtDNA haplogroups

  • U => 50,000 to 60,000 years ago (arose in Western Asia)
  • H => 30,000 to 50,000 years ago (in the Near East – associated with Cro-Magnon in Europe)
  • J => 45,000 years ago (in the Near East)
  • X => over 30,000 years ago (in north-east Europe)
  • I => 30,000 years ago (origin unknown – probably in Europe)
  • W => 25,000 years ago (in north-east Europe or north-west Asia)
  • K => 15,000 years ago (in the Near East)
  • T => 10,000 years ago (in Mesopotamia)
  • V => 10,000 years ago (arose in Iberia and moved to Scandinavia)

Haplogroup H is by far the most common all over Europe, amounting to about 40% of the European population. It is also found (though in lower frequencies) in North Africa, the Middle East, Central Asia, Northern Asia, as well as along the East coast of Africa as far as Madagascar.

The testing of ancient DNA helped understand how long each haplogroup has been in Europe. Only a few such tests have been successfully conducted so far. Mitochondrial DNA was extracted from the skeleton of a 28,000 year-old Cro-Magnon from southern Italy, and the haplogroup matched the Cambridge Reference Sequence (H2b). Still preceding the Neolithic expansion from the Middle East, the 9,000 year-old Cheddar Man was found to belong to haplogroup U5a.

Among Bronze-age mtDNA, the 3,300 year-old Ötzi the Iceman belonged to haplogroup K1. The remains of a family found in a cave in Lichtenstein, dating from 3,000 years ago, all belonged to haplogroup T. Haplogroups I and X were both found in ancient Viking cemeteries. X was also discovered in an Anglo-Saxon tomb in England.

The Gypsies have two mtDNA haplogroups not found in the rest of the European population. About half of them belong to haplogroup M (found throughout East Asia and South Asia, especially in India), and 15% to haplogroup U3 (only found in high frequencies among the Gypsy community).

I, W, X and the Neanderthal debate

I, W and X are all of very ancient European origin. They are estimated to have arisen approximately 30,000 years ago, a few thousand years before the extinction of Neanderthal. Although present in all Europe and a big part of Asia, from the Middle East to Siberia, and even in North America in the case of X, these three haplogroups never exceed more than a few percents of the population in every region (most often under 1%). They are most common in cold, mountainous or desertic climates. The highest densities of X and W are observed in the Caucasus, in North-East Europe, Siberia and Central Asia, while haplogroup I reaches unusually high levels (4 or 5%) in countries like Iceland, Scotland, Norway or Latvia.

One hypothesis is that these mtDNA haplogroups might be the only surviving haplogroups descended from a specific subspecies of Neanderthal. Neanderthals lived in Europe, and as far as North-West Asia and the Middle East, for over 200,000 years. They progressively disappeared over a period of 25,000 years after the arrival of Homo Sapiens from Africa. The most recent skeletons of Neanderthals found in Iberia (dating from 25,000 years ago) show obvious signs of Homo Sapiens admixture. Just like some White Americans nowadays carry Native American or African mtDNA without looking different from a "pure" European, it is thought that Neanderthals left some genes in modern humans, and maybe some mitochondrial lineages.

The Neanderthalian hypothesis is consistent with the estimated age and place of origin of these haplogroups – in Europe or Russia, just before the presumed extinction of Neanderthal. It correlates with the fact that haplogroups I, W and X now make up only a tiny minority of European haplogroups, while the descendants of haplogroup R (H, V, J, T, U and K), representing the better adapted Homo Sapiens, account for over 95% of the modern European population. Homo Sapiens would have progressively outnumbered, then assimilated the last Neanderthals. The same phenomenon is thought to have happened in Asia between the new wave of Homo Sapiens from Africa and the various indigenous species of Homo Erectus (e.g. Peking Man, Java Man, Man of Flores) .

The fact that only the mtDNA line (i.e. the maternal line) of Neanderthal has survived is also concordant. In primitive societies women were very likely to be raped, abducted by another tribe, or spared during tribal warfare and integrated to the winning tribe. A few isolated cases are enough to pass Neanderthalian mtDNA to the Homo Sapiens population.

Due to Neanderthal’s long evolution and their adaptation to extreme climates, including several glaciations, the phylogenic tree of Neanderthal mtDNA could be as diversified, if not more, than that of modern hum