The genetic history of the British Isles is the subject of research within the larger field of human

population genetics Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and po ...

. It has developed in parallel with

DNA test Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

ing technologies capable of identifying genetic similarities and differences between both modern and ancient populations. The conclusions of population genetics regarding the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isl ...

in turn draw upon and contribute to the larger field of understanding the history of the human occupation of the area, complementing work in

linguistics Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Ling ...

archaeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landsc ...

history History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well ...

and

genealogy Genealogy () is the study of families, family history, and the tracing of their lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kin ...

. Research concerning the most important routes of migration into the British Isles is the subject of debate. Apart from the most obvious route across the narrowest point of the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" ( Cotentinais) or ( Jèrriais), ( Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Ka ...

into

Kent Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...

, other routes may have been important over the millennia, including a

land bridge In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonize new lands. A land bridge can be created by marine regression, in which sea leve ...

in the

Mesolithic The Mesolithic ( Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymo ...

period, as well as maritime connections along the Atlantic coasts. The periods of the most important migrations are contested. The

Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several pa ...

introduction of

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

technologies from mainland Europe is frequently proposed as a period of major change in the British Isles. Such technology could either have been learned by locals from a small number of immigrants or have been introduced by

colonists A settler is a person who has migrated to an area and established a permanent residence there, often to colonize the area. A settler who migrates to an area previously uninhabited or sparsely inhabited may be described as a pioneer. Settle ...

who significantly changed the population. Other potentially important historical periods of migration that have been subject to consideration in this field include the introduction of

Celtic languages The Celtic languages (usually , but sometimes ) are a group of related languages descended from Proto-Celtic. They form a branch of the Indo-European language family. The term "Celtic" was first used to describe this language group by Edward ...

and technologies (during the

Bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids suc ...

and

Iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

Ages), the

Roman era In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC ...

, the period of

Anglo-Saxon The Anglo-Saxons were a cultural group who inhabited England in the Early Middle Ages. They traced their origins to settlers who came to Britain from mainland Europe in the 5th century. However, the ethnogenesis of the Anglo-Saxons happened wit ...

influx, the

Viking Vikings ; non, víkingr is the modern name given to 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 se ...

era, the

Norman invasion of 1066 The Norman Conquest (or the Conquest) was the 11th-century invasion and occupation of England by an army made up of thousands of Norman, Breton, Flemish, and French troops, all led by the Duke of Normandy, later styled William the Conque ...

, and the era of the

European wars of religion The European wars of religion were a series of wars waged in Europe during the 16th, 17th and early 18th centuries. Fought after the Protestant Reformation began in 1517, the wars disrupted the religious and political order in the Catholic cou ...

History of research

Early studies by Luigi Cavalli-Sforza used polymorphisms from proteins found within

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

(such as the ABO blood groups, Rhesus blood antigens, HLA loci,

immunoglobulins An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

G6PD Glucose-6-phosphate dehydrogenase (G6PD or G6PDH) () is a cytosolic enzyme that catalyzes the chemical reaction : D-glucose 6-phosphate + NADP+ + H2O 6-phospho-D-glucono-1,5-lactone + NADPH + H+ This enzyme participates in the pentose phosp ...

isoenzyme In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. dif ...

s, amongst others). One of the lasting proposals of this study with regards to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

is that within most of the continent the majority of genetic diversity may best be explained by immigration coming from the southeast towards the northwest or in other words from the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...

towards

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

and

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

. Cavalli-Sforza proposed at the time that the invention of agriculture might be the best explanation for this. With the advent of DNA analysis modern populations were sampled for

mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

to study the female line of descent and

Y chromosome The Y chromosome is one of two sex chromosomes (allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or abs ...

DNA to study male descent. As opposed to large scale sampling within the

autosomal DNA An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes ...

, Y DNA and mitochondrial DNA represent specific types of genetic descent and can therefore reflect only particular aspects of past human movement. Later projects began to use autosomal DNA to gather a more complete picture of an individual's genome. For Britain, major research projects aimed at collecting data include the Oxford Genetic Atlas Project (OGAP) and more recently the '' People of the British Isles'', also associated with Oxford. Owing to the difficulty of modelling the contributions of historical migration events to modern populations based purely on modern genetic data, such studies often varied significantly in their conclusions. One early Y DNA study estimated a complete genetic replacement by the Anglo-Saxons, whilst another argued that it was impossible to distinguish between the contributions of the Anglo-Saxons and Vikings and that the contribution of the latter may even have been higher. A third study argued that there was no Viking influence on British populations at all outside

Orkney Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north ...

. Stephen Oppenheimer and

Bryan Sykes Bryan Clifford Sykes (9 September 1947 – 10 December 2020) was a British geneticist and science writer who was a Fellow of Wolfson College and Emeritus Professor of human genetics at the University of Oxford. In the last decade, improved technologies for extracting ancient DNA have allowed researchers to study the genetic impacts of these migrations in more detail. This led to Oppenheimer and Sykes' conclusions about the origins of the British being seriously challenged, since later research demonstrated that the majority of the DNA of much of continental Europe, including Britain and Ireland, is ultimately derived from Steppe invaders from the east rather than Iberia. This research has also suggested that subsequent migrations, such as that of the Anglo-Saxons, did have large genetic effects (though these effects varied from place to place).Schiffels, S. ''et al.'' (2016
''Iron Age and Anglo-Saxon genomes from East England reveal British migration history''
Nature Communications 7, Article number:10408 doi:10.1038/ncomms10408

Analyses of nuclear and ancient DNA

Paleolithic

After the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eu ...

, there is evidence of repopulation of Britain and Ireland during the late Upper Paleolithic from c. 13,500 BCE. Human skeletal remains from this period are rare. They include a female from Gough’s Cave, an individual who is genetically similar to the c. 15,000 year old individual ('Goyet-Q2') from Goyet Caves, Belgium. The female from Gough’s Cave carried mtDNA U8a, which is found in several individuals of the

Magdalenian The Magdalenian cultures (also Madelenian; French: ''Magdalénien'') are later cultures of the Upper Paleolithic and Mesolithic in western Europe. They date from around 17,000 to 12,000 years ago. It is named after the type site of La Madel ...

culture in Europe, but not in any other early ancient individuals from Britain. A second individual from

Kendrick's Cave Kendrick's Cave on the Great Orme, Llandudno, Wales, was the site of important archaeological finds by Thomas Kendrick in 1880. The site is a small natural cavern on the south of the Great Orme Head, a limestone massif on the seaward side of Llan ...

, a c. 12,000 BCE male, was found to be genetically similar to the Villabruna cluster, also known as Western Hunter-Gatherer ancestry. This ancestry is found in later British Mesolithic individuals. The Kendrick’s Cave individual's mtDNA U5a2 is also found in several British Mesolithic samples.

Mesolithic population

Mesolithic Britons were closely related to other Mesolithic people throughout Western Europe. This population probably had pale-coloured eyes,

lactose intolerance Lactose intolerance is a common condition caused by a decreased ability to digest lactose, a sugar found in dairy products. Those affected vary in the amount of lactose they can tolerate before symptoms develop. Symptoms may include abdominal pai ...

, dark curly or wavy hair and dark to very dark skin.Supplementary Material
(p.18, on Cheddar Man): "This individual has light or blue/green eye colour, it is not light blue, there are elements of brown/yellow in the eye to give a proposed perceived green colour. Better coverage at the low sequenced marker would clarify this but blue/hazel cannot be ruled out. It is certainly not a brown eyed or clear blue-eyed individual... Skin pigmentation ssumptions about missing information omittedThe following range for skin pigmentation prediction is possible for this individual with these parameters:... Dark 0.209 – 0.435 Dark-Black 0.749 – 0.36 Final prediction: Dark/Dark-to-Black skin Explanation: The combined effect of probabilities in the dark and dark-to-black colour categories provide an indication that the individual has darkly pigmented skin, it is unlikely that this individual has the darkest possible skin pigmentation, but it cannot be ruled out as the missing SNP does influence that detail, but certainly skin pigmentation is dark in complexion."

Continental Neolithic farmers

The change to the Neolithic in the British Isles () went along with a significant population shift. Neolithic individuals were close to Iberian and Central European Early and Middle Neolithic populations, modelled as having about 75% ancestry from

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

n farmers with the rest coming from Western Hunter-Gatherers (WHG) in continental Europe. This suggests that farming was brought to the British Isles by sea from north-west mainland Europe, by a population that was, or became in succeeding generations, relatively large. In some regions, British Neolithic individuals had a small amount (about 10%) of WHG excess ancestry when compared with Iberian Early Neolithic farmers, suggesting that there was an additional gene flow from British Mesolithic hunter-gatherers into the newly arrived farmer population: while Neolithic individuals from Wales have no detectable admixture of local Western hunter-gatherer genes, those from South East England and Scotland show the highest additional admixture of local WHG genes, and those from South-West and Central England are intermediate.

Bronze Age European Bell Beaker People

According to Olalde et al. (2018), the spread of the

Bell Beaker The Bell Beaker culture, also known as the Bell Beaker complex or Bell Beaker phenomenon, is an archaeological culture named after the inverted-bell beaker drinking vessel used at the very beginning of the European Bronze Age. Arising from ar ...

culture to Britain from the

lower Rhine The Lower Rhine (german: Niederrhein; kilometres 660 to 1,033 of the river Rhine) flows from Bonn, Germany, to the North Sea at Hook of Holland, Netherlands (including the Nederrijn or "Nether Rhine" within the Rhine–Meuse–Scheldt delta); ...

area in the early Bronze Age introduced high levels of

steppe-related ancestry In archaeogenetics, the term Western Steppe Herders (WSH), or Western Steppe Pastoralists, is the name given to a distinct ancestral component first identified in individuals from the Eneolithic steppe around the turn of the 5th millennium BCE, ...

, resulting in a near-complete change of the local gene pool within a few centuries, replacing about 90% of the local Neolithic-derived lineages between 2,400 BC and 2,000 BC. These people exhibiting the Beaker culture were likely an offshoot of the

Corded Ware The Corded Ware culture comprises a broad archaeological horizon of Europe between ca. 3000 BC – 2350 BC, thus from the late Neolithic, through the Copper Age, and ending in the early Bronze Age. Corded Ware culture encompassed a ...

culture, as they had little genetic affinity to the Iberian Beaker people. With the large steppe-derived component, they had a smaller proportion of continental Neolithic and Western Hunter Gatherer DNA. The Modern British and Irish likely derive most of their ancestry from this Beaker culture population. According to geneticist David Reich, southern Britain saw an increase in Neolithic DNA around the Iron Age to the Roman Period, which may be attributable to a resurgence of the native Neolithic-derived population or to Celtic Iron Age or Roman period migrations. An earlier study had estimated that the modern English population derived somewhat just over half of their ancestry from a combination of Neolithic and Western Hunter Gatherer ancestry, with the steppe-derived (Yamnaya-like) element making up the remainder. Scotland was found to have both more Steppe and more Western Hunter Gatherer ancestry than England. These proportions are similar to other Northwest European populations.

Anglo-Saxons

Researchers have used ancient DNA to determine the nature of the Anglo-Saxon settlement, as well as its impact on modern populations in the British Isles. One 2016 study, using Iron Age and Anglo-Saxon era DNA found at grave sites in Cambridgeshire, calculated that ten modern-day eastern English samples had 38% Anglo-Saxon ancestry on average whilst ten Welsh and Scottish samples each had 30% Anglo-Saxon ancestry, with a large statistical spread in all cases. However, the authors noted that the similarity observed between the various sample groups was possibly due to more recent internal migration. Another 2016 study conducted using evidence from burials found in northern England found that a significant genetic difference was present in bodies from the Iron Age and the Roman period on the one hand and the Anglo-Saxon period on the other. Samples from modern-day Wales were found to be similar to those from the Iron Age and Roman burials whilst samples from much of modern England, East Anglia in particular, were closer to the Anglo-Saxon-era burial. This was found to demonstrate a "profound impact" from the Anglo-Saxon migrations on the modern English gene pool, though no specific percentages were given in the study.Martiniano, R., Caffell, A., Holst, M. et al. Genomic signals of migration and continuity in Britain before the Anglo-Saxons. Nat Commun 7, 10326 (2016). https://doi.org/10.1038/ncomms10326 A third study combined the ancient data from both of the preceding studies and compared it to a large number of modern samples from across Britain and Ireland. This study concluded that modern southern, central and eastern English populations were of "a predominantly Anglo-Saxon-like ancestry" whilst those from northern and southwestern England had a greater degree of indigenous origin. A 2022 study focusing specifically on the question of the Anglo-Saxon settlement sampled 460 northwestern European individuals dated to the medieval period. The study concluded that in eastern England, large-scale immigration, including both men and women, occurred in the post-Roman era, with up to 76% of the ancestry of these individuals deriving from the North Sea coast area of continental Europe. The authors also noted that while a large proportion of the ancestry of the present-day English derives from the Anglo-Saxon migration event, it has been diluted by later migration from a population source similar to that of Iron Age France.

Vikings

Historical and toponymic evidence suggests a substantial Viking migration to many parts of northern Britain; however, particularly in the case of the Danish settlers, differentiating their genetic contribution to modern populations from that of the Anglo-Saxons has posed difficulties. A study published in 2020, which used ancient DNA from across the Viking world in addition to modern data, noted that ancient samples from Denmark showed similarities to samples from both modern Denmark and modern England. Whilst most of this similarity was attributed to the earlier settlement of the Anglo-Saxons, the authors of the study noted that British populations also carried a small amount of "Swedish-like" ancestry that was present in the Danish Vikings but unlikely to have been associated with the Anglo-Saxons. From this, it was calculated that the modern English population has approximately 6% Danish Viking ancestry, with Scottish and Irish populations having up to 16%. Additionally, populations from all areas of Britain and Ireland were found to have 3–4% Norwegian Viking ancestry.

Irish populations

A 2015 study using data from the Neolithic and Bronze Ages showed a considerable genetic difference between individuals during the two periods, which was interpreted as being the result of a migration from the Pontic steppes. The individuals from the latter period, with significant steppe ancestry, showed strong similarities to modern Irish population groups. The study concluded that "these findings together suggest the establishment of central aspects of the Irish genome 4,000 years ago." Another study, using modern autosomal data, found a large degree of genetic similarity between populations from northeastern Ireland, southern Scotland and Cumbria. This was interpreted as reflecting the legacy of the

Plantation of Ulster The Plantation of Ulster ( gle, Plandáil Uladh; Ulster-Scots: ''Plantin o Ulstèr'') was the organised colonisation ('' plantation'') of Ulstera province of Irelandby people from Great Britain during the reign of King James I. Most of th ...

in the 17th century.

Haplogroups

Mitochondrial DNA

Bryan Sykes broke mitochondrial results into twelve haplogroups for various regions of the isles: * Haplogroup H * Haplogroup I * Haplogroup J * Haplogroup T * Haplogroup V * Haplogroup W * Haplogroup X * Haplogroup U ...and within U... :* Haplogroup U2 :* Haplogroup U3 :* Haplogroup U4 :* Haplogroup U5 Sykes found that the maternal haplogroup pattern was similar throughout England but with a distinct trend from east and north to west and south. Minor haplogroups were mainly found in the east of England. Sykes found Haplogroup H to be dominant in Ireland and Wales, though a few differences were found between north, mid and south Wales—there was a closer link between north and mid-Wales than either had with the south. Studies of ancient DNA have demonstrated that ancient Britons and Anglo-Saxon settlers carried a variety of mtDNA haplogroups, though type H was common in both.Schiffels, S. and Sayer, D. (2017) "Investigating Anglo-Saxon migration history with ancient and modern DNA," H.H. Meller, F. Daim, J. Frause and R. Risch (eds) Migration and Integration form Prehistory to the Middle Ages. Tagungen Des Landesmuseums Für Vorgeschichte Halle, Saale

Y chromosome DNA

Sykes also designated five main Y-DNA haplogroups for various regions of Britain and Ireland. *

Haplogroup R1b Haplogroup R1b (R-M343), previously known as Hg1 and Eu18, is a human Y-chromosome haplogroup. It is the most frequently occurring paternal lineage in Western Europe, as well as some parts of Russia (e.g. the Bashkirs) and pockets of Central ...

Haplogroup R1a Haplogroup R1a, or haplogroup R-M420, is a human Y-chromosome DNA haplogroup which is distributed in a large region in Eurasia, extending from Scandinavia and Central Europe to southern Siberia and South Asia. While R1a originated c. 22,000 to ...

* Haplogroup I * Haplogroup E1b1b * Haplogroup J Haplogroup R1b is dominant throughout

Western Europe Western Europe is the western region of Europe. The region's countries and territories vary depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...

. While it was once seen as a lineage connecting Britain and Ireland to Iberia, where it is also common, it is now believed that both R1b and R1a entered Europe with

Indo-European The Indo-European languages are a language family native to the overwhelming majority of Europe, the Iranian plateau, and the northern Indian subcontinent. Some European languages of this family, English, French, Portuguese, Russian, Du ...

migrants likely originating around the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ...

; R1a and R1b are now the most common haplotypes in Europe. One common R1b subclade in Britain is R1b-U106, which reaches its highest frequencies in

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian ...

areas such as southern and eastern

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

and

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...

. Due to its distribution, this subclade is often associated with the

migrations. Ancient DNA has shown that it was also present in Roman Britain, possibly among descendants of Germanic mercenaries. Ireland, Scotland, Wales and northwestern England are dominated by R1b-L21, which is also found in northwestern

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

(

Brittany Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo: ''Bertaèyn'' ) is a peninsula, historical country and cultural area in the west of modern France, covering the western part of what was known as Armorica during the period ...

), the north coast of

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

(

Galicia Galicia may refer to: Geographic regions * Galicia (Spain), a region and autonomous community of northwestern Spain ** Gallaecia, a Roman province ** The post-Roman Kingdom of the Suebi, also called the Kingdom of Gallaecia ** The medieval King ...

), and western

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...

. This lineage is often associated with the historic

Celts The Celts (, see pronunciation for different usages) or Celtic peoples () are. "CELTS location: Greater Europe time period: Second millennium B.C.E. to present ancestry: Celtic a collection of Indo-European peoples. "The Celts, an ancient ...

, as most of the regions where it is predominant have had a significant Celtic language presence into the modern period and associate with a Celtic cultural identity in the present day. It was also present among Celtic Britons in eastern England prior to the Anglo-Saxon and Viking invasions, as well as Roman soldiers in York who were of native descent. There are various smaller and geographically well-defined Y-DNA Haplogroups under R1b in Western Europe. Haplogroup R1a, a close cousin of R1b, is most common in

Eastern Europe Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russia, whi ...

. In Britain, it has been linked to Scandinavian immigration during periods of Viking settlement. 25% of men in Norway belong to this haplogroup; it is much more common in Norway than in the rest of Scandinavia. Around 9% of all Scottish men belong to the Norwegian R1a subclade, which peaks at over 30% in

Shetland Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the n ...

and Orkney. Haplogroup I is a grouping of several quite distantly related lineages. Within Britain, the most common subclade is I1, which also occurs frequently in northwestern continental Europe and southern

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and S ...

, and has thus been associated with the settlement of the Anglo-Saxons and Vikings. An Anglo-Saxon male from northern England who died between the seventh and tenth centuries was determined to have belonged to haplogroup I1. Haplogroups E1b1b and J in Europe are regarded as markers of Neolithic movements from the Middle East to

Southern Europe Southern Europe is the southern region of Europe. It is also known as Mediterranean Europe, as its geography is essentially marked by the Mediterranean Sea. Definitions of Southern Europe include some or all of these countries and regions: Alb ...

and likely to Northern Europe from there. These haplogroups are found most often in Southern Europe and

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

. Both are rare in Northern Europe; E1b1b is found in 1% of Norwegian men, 1.5% of Scottish, 2% of English, 2.5% of Danish, 3% of Swedish and 5.5% of German. It reaches its peak in Europe in

Kosovo Kosovo ( sq, Kosova or ; sr-Cyrl, Косово ), officially the Republic of Kosovo ( sq, Republika e Kosovës, links=no; sr, Република Косово, Republika Kosovo, links=no), is a international recognition of Kosovo, partiall ...

at 47.5% and

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders wi ...

at 30%.

Uncommon Y haplogroups

Geneticists have found that seven men with the surname Revis, which originates in

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...

, carry a genetic signature previously found only in people of

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali ...

n origin. All of the men belonged to Haplogroup A1a (M31), a subclade of Haplogroup A which geneticists believe originated in Eastern or

Southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

. The men are not regarded as

phenotypically In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...

African and there are no documents, anecdotal evidence or oral traditions suggesting that the Revis family has African ancestry. It has been conjectured that the presence of this haplogroup may date from the

when both Africans and Romans of African descent are known to have settled in Britain. According to Bryan Sykes, "although the Romans ruled from AD 43 until 410, they left a tiny genetic footprint." The genetics of some visibly white (European) people in England suggests that they are "descended from north African, Middle Eastern and Roman clans". Geneticists have shown that former American president

Thomas Jefferson Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Fathers of the United States, Founding Father who served as the third president of the United States from 18 ...

, who might have been of Welsh descent, along with two other British men out of 85 British men with the surname Jefferson, carry the rare Y chromosome marker T (formerly called K2). This is typically found in

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historica ...

and the

. Haplogroup T is extremely rare in Europe but phylogenetic network analysis of its Y-STR (short tandem repeat) haplotype shows that it is most closely related to an Egyptian T haplotype, but the presence of scattered and diverse European haplotypes within the network is nonetheless consistent with Jefferson's patrilineage belonging to an ancient and rare indigenous European type.

References

Bibliography

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