Haplogroup I is a
human mitochondrial DNA
Human mitochondrial genetics is the study of the genetics of human mitochondrial DNA (the DNA contained in human mitochondria). The human mitochondrial genome is the entirety of hereditary information contained in human mitochondria. Mitochondr ...
(mtDNA) haplogroup. It is believed to have originated about 21,000 years ago, during the
Last Glacial Maximum
The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago.
Ice sheets covered m ...
(LGM) period in
West Asia
West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...
; ; ). The haplogroup is unusual in that it is now widely distributed geographically, but is common in only a few small areas of
East Africa
East Africa, also known as Eastern Africa or the East of Africa, is a region at the eastern edge of the Africa, African continent, distinguished by its unique geographical, historical, and cultural landscape. Defined in varying scopes, the regi ...
, West Asia and
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
. It is especially common among the
El Molo and
Rendille peoples of Kenya, various regions of
Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
, the
Lemko people of Slovakia, Poland and Ukraine, the island of
Krk in Croatia, the department of
Finistère
Finistère (, ; ) is a Departments of France, department of France in the extreme west of Brittany. Its prefecture is Quimper and its largest city is Brest, France, Brest. In 2019, it had a population of 915,090.[Scotland
Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...]
and
Ireland
Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...
.
Origin
Haplogroup I is a descendant (
subclade
In genetics, a subclade is a subgroup of a haplogroup.
Naming convention
Although human mitochondrial DNA (mtDNA) and Y chromosome DNA (Y-DNA) haplogroups and subclades are named in a similar manner, their names belong to completely separate syst ...
) of haplogroup N1a1b and sibling of haplogroup N1a1b1 . It is believed to have arisen somewhere in West Asia between 17,263 and 24,451 years
before present
Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because ...
(BP) , with coalescence age of 20.1 thousand years ago . It has been suggested that its origin may be in Iran or more generally the Near East . It has diverged to at least seven distinct clades i.e. branches I1–I7, dated between 16–6.8 thousand years . The hypothesis about its Near Eastern origin is based on the fact that all haplogroup I clades, especially those from Late Glacial period (I1, I4, I5, and I6), include mitogenomes from the Near East . The age estimates and dispersal of some subclades (I1, I2’3, I5) are similar to those of major subclades of the mtDNA haplogroups
J and
T, indicating possible dispersal of the I haplogroup into Europe during the Late Glacial period (c. 18–12 kya) and postglacial period (c. 10–11 kya), several millennia before the European Neolithic period. Some subclades (I1a1, I2, I1c1, I3) show signs of the Neolithic diffusion of agriculture and pastoralism within Europe .
A similar view puts more emphasis on the
Persian Gulf
The Persian Gulf, sometimes called the Arabian Gulf, is a Mediterranean seas, mediterranean sea in West Asia. The body of water is an extension of the Arabian Sea and the larger Indian Ocean located between Iran and the Arabian Peninsula.Un ...
region of the Near East .
Distribution

Haplogroup I is found at moderate to low frequencies in
East Africa
East Africa, also known as Eastern Africa or the East of Africa, is a region at the eastern edge of the Africa, African continent, distinguished by its unique geographical, historical, and cultural landscape. Defined in varying scopes, the regi ...
,
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
,
West Asia
West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...
and
South Asia
South Asia is the southern Subregion#Asia, subregion of Asia that is defined in both geographical and Ethnicity, ethnic-Culture, cultural terms. South Asia, with a population of 2.04 billion, contains a quarter (25%) of the world's populatio ...
. In addition to the confirmed seven clades, the rare basal/paraphyletic clade I* has been observed in three individuals; two from
Somalia
Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...
and one from
Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
.
Africa
The highest frequencies of mitochondrial haplogroup I observed so far appear in the
Cushitic
The Cushitic languages are a branch of the Afroasiatic language family. They are spoken primarily in the Horn of Africa, with minorities speaking Cushitic languages to the north in Egypt and Sudan, and to the south in Kenya and Tanzania. As of 2 ...
-speaking
El Molo (23%) and
Rendille (>17%) in northern Kenya . The clade is also found at comparable frequencies among the
Soqotri (~22%).
Asia
Haplogroup I is present across West Asia and Central Asia, and is also found at trace frequencies in South Asia. Its highest frequency area is perhaps in northern Iran (9.7%). Terreros 2011 notes that it also has high diversity there and reiterates past studies that have suggested that this may be its place of origin. Found in Svan population from Georgia(Caucasus) I* 4.2%."Sequence polymorphisms of the mtDNA control region in a human isolate: the Georgians from Swanetia."Alfonso-Sánchez MA1, Martínez-Bouzas C, Castro A, Peña JA, Fernández-Fernández I, Herrera RJ, de Pancorbo MM. The table below shows some of the populations where it has been detected.
Europe
Eastern Europe
In Eastern Europe, the frequency of haplogroup I is generally lower than in Western Europe (1 to 3 percent), but its frequency is more consistent between populations with fewer places of extreme highs or lows. There are two notable exceptions. Nikitin 2009 found that
Lemkos
Lemkos (; ; ; ) are an ethnic group inhabiting the Lemko Region (; ) of Carpathian Rus', an ethnographic region in the Carpathian Mountains and foothills spanning Ukraine, Slovakia, and Poland.
Lemkos are often considered to be a sub-group of ...
(a sub- or co-ethnic group of
Rusyns
Rusyns, also known as Carpatho-Rusyns, Carpatho-Russians, Ruthenians, or Rusnaks, are an East Slavs, East Slavic ethnic group from the Carpathian Rus', Eastern Carpathians in Central Europe. They speak Rusyn language, Rusyn, an East Slavic lan ...
) in the
Carpathian Mountains
The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe and Southeast Europe. Roughly long, it is the third-longest European mountain range after the Ural Mountains, Urals at and the Scandinav ...
have the "highest frequency of haplogroup I (11.3%) in Europe, identical to that of the population of
Krk Island (Croatia) in the Adriatic Sea".
[Nikitin 2009: 6/53 in Lemkos]
''"Lemkos shared the highest frequency of haplogroup I ever reported and the highest frequency of haplogroup M* in the region."''[: 15/133]
Western Europe
In Western Europe, haplogroup I is most common in Northwestern Europe (Norway, the Isle of Skye, and the British Isles). The frequency in these areas is between 2 and 5 percent. Its highest frequency in Brittany, France where it is over 9 percent of the population in
Finistère
Finistère (, ; ) is a Departments of France, department of France in the extreme west of Brittany. Its prefecture is Quimper and its largest city is Brest, France, Brest. In 2019, it had a population of 915,090.[Sardinia
Sardinia ( ; ; ) is the Mediterranean islands#By area, second-largest island in the Mediterranean Sea, after Sicily, and one of the Regions of Italy, twenty regions of Italy. It is located west of the Italian Peninsula, north of Tunisia an ...]
was found a sample with the subclade I3 dated to 9124–7851 BC , while in the Near East, in Levant was found a sample with yet-not-defined subclade dated 8850–8750 BC, while in Iran was found a younger sample with subclade I1c dated to 3972–3800 BC . In Neolithic Spain (c. 6090–5960 BC in
Paternanbidea,
Navarre
Navarre ( ; ; ), officially the Chartered Community of Navarre, is a landlocked foral autonomous community and province in northern Spain, bordering the Basque Autonomous Community, La Rioja, and Aragon in Spain and New Aquitaine in France. ...
) was found a sample with yet-not-defined subclade . Haplogroup I displays a strong connection with the
Indo-European migrations
The Indo-European migrations are hypothesized migrations of Proto-Indo-Europeans, peoples who spoke Proto-Indo-European language, Proto-Indo-European (PIE) and the derived Indo-European languages, which took place from around 4000 to 1000 BCE, ...
; especially its I1, I1a1 and I3a subclades, which have been found in
Poltavka and
Srubnaya cultures in
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
(Mathieson 2015), among ancient
Scythia
Scythia (, ) or Scythica (, ) was a geographic region defined in the ancient Graeco-Roman world that encompassed the Pontic steppe. It was inhabited by Scythians, an ancient Eastern Iranian equestrian nomadic people.
Etymology
The names ...
ns (Der Sarkissian 2011), and in
Corded Ware and
Unetice Culture burials in Saxony ().I3a has also been found in the Unetice Culture in Lubingine, Germany 2,200 B.C. to 1,800 B.C. courtesy article on Unetice Culture Wikipedia of 2 Skeletons that were DNA tested. Haplogroup I (with undetermined subclades) has also been noted at significant frequencies in more recent historic grave sites ( and ).
In 2013, ''
Nature
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'' announced the publication of the first genetic study utilizing
next-generation sequencing
Massive parallel sequencing or massively parallel sequencing is any of several high-throughput approaches to DNA sequencing using the concept of massively parallel processing; it is also called next-generation sequencing (NGS) or second-generation ...
to ascertain the ancestral lineage of an
Ancient Egypt
Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...
ian individual. The research was led by Carsten Pusch of the
University of Tübingen
The University of Tübingen, officially the Eberhard Karl University of Tübingen (; ), is a public research university located in the city of Tübingen, Baden-Württemberg, Germany.
The University of Tübingen is one of eleven German Excellenc ...
in
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
and Rabab Khairat, who released their findings in the ''Journal of Applied Genetics''. DNA was extracted from the heads of five Egyptian mummies that were housed at the institution. All the specimens were dated to between 806 BC and 124 AD, a time frame corresponding with the
Late Dynastic and
Ptolemaic periods. The researchers observed that one of the mummified individuals likely belonged to the I2 subclade. Haplogroup I has also been found among
ancient Egypt
Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...
ian mummies excavated at the
Abusir el-Meleq archaeological site in Middle Egypt, which date from the Pre-Ptolemaic/late
New Kingdom,
Ptolemaic, and
Roman periods.
Haplogroup I5 has also been observed among specimens at the mainland cemetery in
Kulubnarti,
Sudan
Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...
, which date from the
Early Christian
Early Christianity, otherwise called the Early Church or Paleo-Christianity, describes the historical era of the Christian religion up to the First Council of Nicaea in 325. Christianity spread from the Levant, across the Roman Empire, and be ...
period (AD 550–800).
Samples with determined subclades
Samples with unknown subclades
The frequency of haplogroup I may have undergone a reduction in Europe following the Middle Ages. An overall frequency of 13% was found in ancient Danish samples from the Iron Age to the Medieval Age (including
Vikings
Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden),
who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...
) from
Denmark
Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...
and
Scandinavia
Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...
compared to only 2.5% in modern samples. As haplogroup I is not observed in any ancient Italian, Spanish
ontradicted by the recent research as have been found in pre-Neolithic Italy as well Neolithic Spain British, central European populations, early central European farmers and Neolithic samples, according to the authors "Haplogroup I could, therefore, have been an ancient Southern Scandinavian type "diluted" by later immigration events" .
Subclades
Tree
This phylogenetic tree of haplogroup I subclades with time estimates is based on the paper and published research .
Distribution
I1
It formed during the Last Glacial pre-warming period. It is found mainly in Europe, Near East, occasionally in North Africa and the Caucasus.
It is the most frequent clade of the haplogroup .
=I1a
=
The subclade frequency peaks (circa 2.8%) are mostly located in North-Eastern Europe .
I1a1
I1a1a
I1a1a1
I1a1a2
I1a1a3
I1a1a3a
I1a1b
I1a1c
I1a1d
I1a1e
=I1b
=
=I1c
=
I1c1
I1c1a1
I1c1a2
=I1d
=
=I1e
=
=I1f
=
I2'3
It is the common root clade for subclades I2 and I3. There's a sample from Tanzania with which I2'3 shares a variant at position 152 from the root node of haplogroup I, and this "node 152" could be upstream I2'3s clade . Both I2 and I3 might have formed during the Holocene period, and most of their subclades are from Europe, only few from the Near East . Examples of this ancestral branch have not been documented.
=I2
=
I2a
I2a1
I2a1a
I2a2
I2a3
I2b
I2c
I2d
I2e
=I3
=
I3a
I3a1
I3b
I3c
I3d
I4
The clade splits into subclades I4a and newly defined I4b, with samples found in Europe, the Near East and the Caucasus .
=I4a
=
I4a1
I4a2
=I4b
=
I5
Is the second most frequent clade of the haplogroup. Its subclades are found in Europe, e.g. I5a1, and the Near East, e.g. I5a2a and I5b .
=I5a
=
I5a1
I5a1a
I5a1b
I5a1c
I5a2
I5a2a
I5a3
I5a4
=I5b
=
=I5c
=
I5c1
I6
The subclade is very rare, found until July 2013 only in four samples from the Near East .
=I6a
=
I7
It is the rarest defined subclade, until July 2013 found only in two samples from the Near East and the Caucasus .
See also
Genetics
Backbone mtDNA Tree
References
Footnotes
Works cited
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External links
*General
**Ian Logan'
Mitochondrial DNA Site**Mannis van Oven'
*Haplogroup I
Family Tree DNA – mtDNA Haplogroup I Project**Family Tree DNA's mtDNA Haplotree
Haplogroup I**YFull MTree'
Haplogroup I**MITOMAP'
Haplogroup I
{{DEFAULTSORT:Haplogroup I (Mtdna)
I