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Haplogroup U (mtDNA)



Haplogroup U
Time of origin 55000 years before present
Place of origin Western Asia
Ancestral haplogroup R
Descendant haplogroups U1, U2, U3, U4, U5, U6, K
Defining mutations 73, 7028, 11719, 12308, 14766

In human genetics, Haplogroup U is a human mitochondrial DNA (mtDNA) haplogroup, a group of people who descend from a woman in the Haplogroup R (mtDNA) branch of the Genographic tree, who lived around 50,000 years ago. Her descendants gave birth to several different subgroups, some of which exhibit specific geographic homelands. The old age has led to a wide distribution of the descendant subgroups that harbor specific European, northern African, Indian, Arab, northern Caucasus Mountains and the Near East clades.[1]

Contents

Subdivisions

Haplogroup U is subdivided into Haplogroups U1-U8 and has a parallel Haplogroup K.

Haplogroup U1

Haplogroup U2

Haplogroup U3

Haplogroup U3 is defined by the HVR1 transition A16343G. It is found at low levels throughout Europe (about 1% of the population), the Near East (about 2.5% of the population), and Central Asia (1%). U3 is present at higher levels among populations in the Caucasus (about 6%) and among Lithuanian, Polish, and Spanish Romani populations (36-56%). [2] [3] [4]

Haplogroup U4

Haplogroup U4 has its origin in the Upper Palaeolithic, dating to approximately 25,000 years ago. It is widely distributed in Europe, and has been implicated in the expansion of modern humans into Europe occurring before the Last Glacial Maximum.

Haplogroup U5

The oldest mtDNA in Europe that's human, Homo Sapien and not Neanderthal or other archaic individual is U5. The age of U5 is estimated at 50,000 but could be as old as 60,500 years. The first place scientists find U5 in Europe is in Cyrenaica, and artifacts are found in Iberia, as it's the first in Europe and evolved in Europe.

The presence of haplogroup U5 in Europe pre-dates the expansion of agriculture in Europe. Bryan Sykes' popular book The Seven Daughters of Eve says it shows up 45,000-50,000 years ago in Delphi, Greece and named the originator of haplogroup U5 Ursula. It shows That U5 is the first out of Africa into Europe, and that it shows up as the first Europeans in two places, Delphi and Spain around 50,000 years ago.

By another source haplogroup U5, age is estimated at about 52,000 kya, being the oldest subclade of haplogroup U.[5] Haplogroup U5 and its subclades are most common in Sami, Finns, and Estonians, but it is spread widely at lower levels throughout Europe. U5 is found also in small frequencies and at much lower diversity in near East suggesting back-migration of people from northern Europe to south.[1]

Haplogroup U5a1a lineage within haplogroup U5 arose in Europe approximately 30,000 years ago, and is mainly found in northwest Europe. In the context of its rather ancient origin, the modern distribution of haplogroup U5a1 suggests that individuals bearing this haplogroup were part the initial expansion tracking the retreat of ice sheets from Europe. Bryan Sykes in his Seven Daughters of Eve book named this mtDNA haplogroup Ursula.

U5 had a common ancestor with its sister group, U6. What's interesting is that U5 and U6 are "sister mtDNA groups" with a common ancestor in N. Africa. Each mtDNA group has a sister group. A large proportion of Canary Islander are U6. The medieval Guanches of the Canary Islands also had U6. There was a lot of interbreeding in paleolithic times between U5 and U6. The Berbers are high in U6 mtDNA today.

U5 is the most ancient mtDNA in Europe (50,000 years to 60,500).


  • Mitochondrial DNA and human evolution: In search of Eve
  • National Geographic's Genographic project
  • The Real Eve: Modern Man's Journey Out of Africa, Stephen Oppenheimer, Carroll & Graf, New York, 2003.
  • Brian Hamman's Clan Ursula (U5 sub-group) Website
  • MtDNA Haplogroup U5 Webpage at WorldFamilies.net

Haplogroup U6

Haplogroup U6 is a group of people who descend from a woman in the Haplogroup R (mtDNA) branch of the Genographic tree. It is common (around 10% of the people) [1] in North Africa and the Canary Islands. It is also found in the Iberian peninsula and British islands due to ancient gene flow from North Africa.

Haplogroup U7

Many European populations lack Haplogroup U7, but its frequency climbs over 4% in the Near East and up to 5% in Pakistan, reaching nearly 10% level in Iranians. In India, haplogroup U7 frequency peaks at over 12% in Gujarat, the westernmost state of India, while for the whole of India its frequency stays around 2%. Expansion times and haplotype diversities for the Indian and Near and Middle Eastern U7 mtDNAs are strikingly similar. The possible homeland of this haplogroup spans Indian Gujarat and Iran because from there its frequency declines steeply both to the east and to the west. If the origin were in Iran rather than in India, then its equally high frequency as well as diversity in Gujarat favors a scenario whereby U7 has been introduced to the coastal western India either very early, or by multiple founders. [2].

Haplogroup U8

The Basques have the most ancestral phylogeny in Europe for the mitochondrial haplogroup U8a, a rare subgroup of U8, placing the Basque origin of this lineage in the Upper Palaeolithic. The lack of U8a lineages in Africa suggests that their ancestors may have originated from West Asia. [6]

See also

Notes

  1. ^ a b c The Genographic Project at National Geographic
  2. ^ http://evolutsioon.ut.ee/publications/Richards2000.pdf
  3. ^ http://www.journals.uchicago.edu/cgi-bin/resolve?id=doi:10.1086/383236
  4. ^ http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1529-8817.2005.00222.x
  5. ^ Barbujani G, Bertorelle G. "Genetics and the population history of Europe." Proceedings of the National Academy of Sciences, 2001.[1]
  6. ^ Gonzalez AM, Garcia O, Larruga JM, Cabrera VM. The mitochondrial lineage U8a reveals a Paleolithic settlement in the Basque country BMC Genomics 2006, 7:124

Human mitochondrial DNA (mtDNA) haplogroups

  most recent common mt-ancestor    
L0   L1  
L2 L3   L4 L5 L6 L7
  M N  
CZ D E G Q   A I O   R   S W X Y
C Z B F pre-HV   pre-JT P  UK
HV JT U K
H V J T
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Haplogroup_U_(mtDNA)". A list of authors is available in Wikipedia.
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