Myths of British ancestry
STEPHEN OPPENHEIMER
PROSPECT MAGAZINE
OCTOBER 2006 — ISSUE 127
Everything you know about British and Irish ancestry is wrong. Our ancestors were Basques, not Celts. The Celts were not wiped out by the Anglo-Saxons, in fact neither had much impact on the genetic stock of these islands
The fact that the British and the Irish both live on islands gives them a misleading sense of security about their unique historical identities. But do we really know who we are, where we come from and what defines the nature of our genetic and cultural heritage? Who are and were the Scots, the Welsh, the Irish and the English? And did the English really crush a glorious Celtic heritage?
Everyone has heard of Celts, Anglo-Saxons and Vikings. And most of us are familiar with the idea that the English are descended from Anglo-Saxons, who invaded eastern England after the Romans left, while most of the people in the rest of the British Isles derive from indigenous Celtic ancestors with a sprinkling of Viking blood around the fringes.
Yet there is no agreement among historians or archaeologists on the meaning of the words “Celtic” or “Anglo-Saxon.” What is more, new evidence from genetic analysis (see note below) indicates that the Anglo-Saxons and Celts, to the extent that they can be defined genetically, were both small immigrant minorities. Neither group had much more impact on the British Isles gene pool than the Vikings, the Normans or, indeed, immigrants of the past 50 years.
The genetic evidence shows that three quarters of our ancestors came to this corner of Europe as hunter-gatherers, between 15,000 and 7,500 years ago, after the melting of the ice caps but before the land broke away from the mainland and divided into islands. Our subsequent separation from Europe has preserved a genetic time capsule of southwestern Europe during the ice age, which we share most closely with the former ice-age refuge in the Basque country. The first settlers were unlikely to have spoken a Celtic language but possibly a tongue related to the unique Basque language.
Another wave of immigration arrived during the Neolithic period, when farming developed about 6,500 years ago. But the English still derive most of their current gene pool from the same early Basque source as the Irish, Welsh and Scots. These figures are at odds with the modern perceptions of Celtic and Anglo-Saxon ethnicity based on more recent invasions. There were many later invasions, as well as less violent immigrations, and each left a genetic signal, but no individual event contributed much more than 5 per cent to our modern genetic mix.
The fact that the British and the Irish both live on islands gives them a misleading sense of security about their unique historical identities. But do we really know who we are, where we come from and what defines the nature of our genetic and cultural heritage? Who are and were the Scots, the Welsh, the Irish and the English? And did the English really crush a glorious Celtic heritage?
Everyone has heard of Celts, Anglo-Saxons and Vikings. And most of us are familiar with the idea that the English are descended from Anglo-Saxons, who invaded eastern England after the Romans left, while most of the people in the rest of the British Isles derive from indigenous Celtic ancestors with a sprinkling of Viking blood around the fringes.
Yet there is no agreement among historians or archaeologists on the meaning of the words “Celtic” or “Anglo-Saxon.” What is more, new evidence from genetic analysis (see note below) indicates that the Anglo-Saxons and Celts, to the extent that they can be defined genetically, were both small immigrant minorities. Neither group had much more impact on the British Isles gene pool than the Vikings, the Normans or, indeed, immigrants of the past 50 years.
The genetic evidence shows that three quarters of our ancestors came to this corner of Europe as hunter-gatherers, between 15,000 and 7,500 years ago, after the melting of the ice caps but before the land broke away from the mainland and divided into islands. Our subsequent separation from Europe has preserved a genetic time capsule of southwestern Europe during the ice age, which we share most closely with the former ice-age refuge in the Basque country. The first settlers were unlikely to have spoken a Celtic language but possibly a tongue related to the unique Basque language.
Another wave of immigration arrived during the Neolithic period, when farming developed about 6,500 years ago. But the English still derive most of their current gene pool from the same early Basque source as the Irish, Welsh and Scots. These figures are at odds with the modern perceptions of Celtic and Anglo-Saxon ethnicity based on more recent invasions. There were many later invasions, as well as less violent immigrations, and each left a genetic signal, but no individual event contributed much more than 5 per cent to our modern genetic mix.
Celtic languages and the people who brought them probably first arrived during the Neolithic period. The regions we now regard as Celtic heartlands actually had less immigration from the continent during this time than England. Ireland, being to the west, has changed least since the hunter-gatherer period and received fewer subsequent migrants (about 12 per cent of the population) than anywhere else. Wales and Cornwall have received about 20 per cent, Scotland and its associated islands 30 per cent, while eastern and southern England, being nearer the continent, has received one third of its population from outside over the past 6,500 years. These estimates, set out in my book The Origins of the British, come from tracing individual male gene lines from continental Europe to the British Isles and dating each one (see box at bottom of page).
If the Celts were not our main aboriginal stock, how do we explain the wide historical distribution and influence of Celtic languages? There are many examples of language change without significant population replacement; even so, some people must have brought Celtic languages to our isles. So where did they come from, and when?
The orthodox view of the origins of the Celts turns out to be an archaeological myth left over from the 19th century. Over the past 200 years, a myth has grown up of the Celts as a vast, culturally sophisticated but warlike people from central Europe, north of the Alps and the Danube, who invaded most of Europe, including the British Isles, during the iron age, around 300 BC.
Central Europe during the last millennium BC certainly was the time and place of the exotic and fierce Hallstatt culture and, later, the La Tène culture, with their prestigious, iron-age metal jewellery wrought with intricately woven swirls. Hoards of such jewellery and weapons, some fashioned in gold, have been dug up in Ireland, seeming to confirm central Europe as the source of migration. The swirling style of decoration is immortalised in such cultural icons as the Book of Kells, the illuminated Irish manuscript (Trinity College, Dublin), and the bronze Battersea shield (British Museum), evoking the western British Isles as a surviving remnant of past Celtic glory. But unfortunately for this orthodoxy, these artistic styles spread generally in Europe as cultural fashions, often made locally. There is no evidence they came to Britain and Ireland as part of an invasion.
Many archaeologists still hold this view of a grand iron-age Celtic culture in the centre of the continent, which shrank to a western rump after Roman times. It is also the basis of a strong sense of ethnic identity that millions of members of the so-called Celtic diaspora hold. But there is absolutely no evidence, linguistic, archaeological or genetic, that identifies the Hallstatt or La Tène regions or cultures as Celtic homelands. The notion derives from a mistake made by the historian Herodotus 2,500 years ago when, in a passing remark about the “Keltoi,” he placed them at the source of the Danube, which he thought was near the Pyrenees. Everything else about his description located the Keltoi in the region of Iberia.
The late 19th-century French historian Marie Henri d’Arbois de Jubainville decided that Herodotus had meant to place the Celtic homeland in southern Germany. His idea has remained in the books ever since, despite a mountain of other evidence that Celts derived from southwestern Europe. For the idea of the south German “Empire of the Celts” to survive as the orthodoxy for so long has required determined misreading of texts by Caesar, Strabo, Livy and others. And the well-recorded Celtic invasions of Italy across the French Alps from the west in the 1st millennium BC have been systematically reinterpreted as coming from Germany, across the Austrian Alps.
De Jubainville’s Celtic myth has been deconstructed in two recent sceptical publications: The Atlantic Celts: Ancient People or Modern Invention by Simon James (1999), and The Celts: Origins, Myths and Inventions by John Collis (2003). Nevertheless, the story lingers on in standard texts and notably in The Celts, a Channel 4 documentary broadcast in February. “Celt” is now a term that sceptics consider so corrupted in the archaeological and popular literature that it is worthless.
This is too drastic a view. It is only the central European homeland theory that is false. The connection between modern Celtic languages and those spoken in southwest Europe during Roman times is clear and valid. Caesar wrote that the Gauls living south of the Seine called themselves Celts. That region, in particular Normandy, has the highest density of ancient Celtic place-names and Celtic inscriptions in Europe. They are common in the rest of southern France (excluding the formerly Basque region of Gascony), Spain, Portugal and the British Isles. Conversely, Celtic place-names are hard to find east of the Rhine in central Europe.
Given the distribution of Celtic languages in southwest Europe, it is most likely that they were spread by a wave of agriculturalists who dispersed 7,000 years ago from Anatolia, travelling along the north coast of the Mediterranean to Italy, France, Spain and then up the Atlantic coast to the British Isles. There is a dated archaeological trail for this. My genetic analysis shows exact counterparts for this trail both in the male Y chromosome and the maternally transmitted mitochondrial DNA right up to Cornwall, Wales, Ireland and the English south coast.
Further evidence for the Mediterranean origins of Celtic invaders is preserved in medieval Gaelic literature. According to the orthodox academic view of “iron-age Celtic invasions” from central Europe, Celtic cultural history should start in the British Isles no earlier than 300 BC. Yet Irish legend tells us that all six of the cycles of invasion came from the Mediterranean via Spain, during the late Neolithic to bronze age, and were completed 3,700 years ago.
If the Celts were not our main aboriginal stock, how do we explain the wide historical distribution and influence of Celtic languages? There are many examples of language change without significant population replacement; even so, some people must have brought Celtic languages to our isles. So where did they come from, and when?
The orthodox view of the origins of the Celts turns out to be an archaeological myth left over from the 19th century. Over the past 200 years, a myth has grown up of the Celts as a vast, culturally sophisticated but warlike people from central Europe, north of the Alps and the Danube, who invaded most of Europe, including the British Isles, during the iron age, around 300 BC.
Central Europe during the last millennium BC certainly was the time and place of the exotic and fierce Hallstatt culture and, later, the La Tène culture, with their prestigious, iron-age metal jewellery wrought with intricately woven swirls. Hoards of such jewellery and weapons, some fashioned in gold, have been dug up in Ireland, seeming to confirm central Europe as the source of migration. The swirling style of decoration is immortalised in such cultural icons as the Book of Kells, the illuminated Irish manuscript (Trinity College, Dublin), and the bronze Battersea shield (British Museum), evoking the western British Isles as a surviving remnant of past Celtic glory. But unfortunately for this orthodoxy, these artistic styles spread generally in Europe as cultural fashions, often made locally. There is no evidence they came to Britain and Ireland as part of an invasion.
Many archaeologists still hold this view of a grand iron-age Celtic culture in the centre of the continent, which shrank to a western rump after Roman times. It is also the basis of a strong sense of ethnic identity that millions of members of the so-called Celtic diaspora hold. But there is absolutely no evidence, linguistic, archaeological or genetic, that identifies the Hallstatt or La Tène regions or cultures as Celtic homelands. The notion derives from a mistake made by the historian Herodotus 2,500 years ago when, in a passing remark about the “Keltoi,” he placed them at the source of the Danube, which he thought was near the Pyrenees. Everything else about his description located the Keltoi in the region of Iberia.
The late 19th-century French historian Marie Henri d’Arbois de Jubainville decided that Herodotus had meant to place the Celtic homeland in southern Germany. His idea has remained in the books ever since, despite a mountain of other evidence that Celts derived from southwestern Europe. For the idea of the south German “Empire of the Celts” to survive as the orthodoxy for so long has required determined misreading of texts by Caesar, Strabo, Livy and others. And the well-recorded Celtic invasions of Italy across the French Alps from the west in the 1st millennium BC have been systematically reinterpreted as coming from Germany, across the Austrian Alps.
De Jubainville’s Celtic myth has been deconstructed in two recent sceptical publications: The Atlantic Celts: Ancient People or Modern Invention by Simon James (1999), and The Celts: Origins, Myths and Inventions by John Collis (2003). Nevertheless, the story lingers on in standard texts and notably in The Celts, a Channel 4 documentary broadcast in February. “Celt” is now a term that sceptics consider so corrupted in the archaeological and popular literature that it is worthless.
This is too drastic a view. It is only the central European homeland theory that is false. The connection between modern Celtic languages and those spoken in southwest Europe during Roman times is clear and valid. Caesar wrote that the Gauls living south of the Seine called themselves Celts. That region, in particular Normandy, has the highest density of ancient Celtic place-names and Celtic inscriptions in Europe. They are common in the rest of southern France (excluding the formerly Basque region of Gascony), Spain, Portugal and the British Isles. Conversely, Celtic place-names are hard to find east of the Rhine in central Europe.
Given the distribution of Celtic languages in southwest Europe, it is most likely that they were spread by a wave of agriculturalists who dispersed 7,000 years ago from Anatolia, travelling along the north coast of the Mediterranean to Italy, France, Spain and then up the Atlantic coast to the British Isles. There is a dated archaeological trail for this. My genetic analysis shows exact counterparts for this trail both in the male Y chromosome and the maternally transmitted mitochondrial DNA right up to Cornwall, Wales, Ireland and the English south coast.
Further evidence for the Mediterranean origins of Celtic invaders is preserved in medieval Gaelic literature. According to the orthodox academic view of “iron-age Celtic invasions” from central Europe, Celtic cultural history should start in the British Isles no earlier than 300 BC. Yet Irish legend tells us that all six of the cycles of invasion came from the Mediterranean via Spain, during the late Neolithic to bronze age, and were completed 3,700 years ago.
Anglo-Saxon ethnic cleansing?
The other myth I was taught at school, one which persists to this day, is that the English are almost all descended from 5th-century invaders, the Angles, Saxons and Jutes, from the Danish peninsula, who wiped out the indigenous Celtic population of England.
The story originates with the clerical historians of the early dark ages. Gildas (6th century AD) and Bede (7th century) tell of Saxons and Angles invading over the 5th and 6th centuries. Gildas, in particular, sprinkles his tale with “rivers of blood” descriptions of Saxon massacres. And then there is the well-documented history of Anglian and Saxon kingdoms covering England for 500 years before the Norman invasion.
But who were those Ancient Britons left in England to be slaughtered when the legions left? The idea that the Celts were eradicated—culturally, linguistically and genetically—by invading Angles and Saxons derives from the idea of a previously uniformly Celtic English landscape. But the presence in Roman England of some Celtic personal and place-names doesn’t mean that all ancient Britons were Celts or Celtic-speaking.
The genocidal view was generated, like the Celtic myth, by historians and archaeologists over the last 200 years. With the swing in academic fashion against “migrationism” (seeing the spread of cultural influence as dependent on significant migrations) over the past couple of decades, archaeologists are now downplaying this story, although it remains a strong underlying perspective in history books.
Some geneticists still cling to the genocide story. Research by several genetics teams associated with University College London has concentrated in recent years on proving the wipeout view on the basis of similarities of male Y chromosome gene group frequency between Frisia/north Germany and England. One of the London groups attracted press attention in July by claiming that the close similarities were the result of genocide followed by a social-sexual apartheid that enhanced Anglo-Saxon reproductive success over Celtic.
The problem is that the English resemble in this way all the other countries of northwest Europe as well as the Frisians and Germans. Using the same method (principal components analysis, see note below), I have found greater similarities of this kind between the southern English and Belgians than the supposedly Anglo-Saxon homelands at the base of the Danish peninsula. These different regions could not all have been waiting their turn to commit genocide on the former Celtic population of England. The most likely reason for the genetic similarities between these neighbouring countries and England is that they all had similar prehistoric settlement histories.
When I looked at exact gene type matches between the British Isles and the continent, there were indeed specific matches between the continental Anglo-Saxon homelands and England, but these amounted to only 5 per cent of modern English male lines, rising to 15 per cent in parts of Norfolk where the Angles first settled. There were no such matches with Frisia, which tends to confirm a specific Anglo-Saxon event since Frisia is closer to England, so would be expected to have more matches.
When I examined dates of intrusive male gene lines to look for those coming in from northwest Europe during the past 3,000 years, there was a similarly low rate of immigration, by far the majority arriving in the Neolithic period. The English maternal genetic record (mtDNA) is consistent with this and contradicts the Anglo-Saxon wipeout story. English females almost completely lack the characteristic Saxon mtDNA marker type still found in the homeland of the Angles and Saxons. The conclusion is that there was an Anglo-Saxon invasion, but of a minority elite type, with no evidence of subsequent “sexual apartheid.”
The orthodox view is that the entire population of the British Isles, including England, was Celtic-speaking when Caesar invaded. But if that were the case, a modest Anglo-Saxon invasion is unlikely to have swept away all traces of Celtic language from the pre-existing population of England. Yet there are only half a dozen Celtic words in English, the rest being mainly Germanic, Norman or medieval Latin. One explanation is that England was not mainly Celtic-speaking before the Anglo-Saxons. Consider, for example, the near-total absence of Celtic inscriptions in England (outside Cornwall), although they are abundant in Ireland, Wales, Scotland and Brittany.
Who was here when the Romans came?
So who were the Britons inhabiting England at the time of the Roman invasion? The history of pre-Roman coins in southern Britain reveals an influence from Belgic Gaul. The tribes of England south of the Thames and along the south coast during Caesar’s time all had Belgic names or affiliations. Caesar tells us that these large intrusive settlements had replaced an earlier British population, which had retreated to the hinterland of southeast England. The latter may have been the large Celtic tribe, the Catuvellauni, situated in the home counties north of the Thames. Tacitus reported that between Britain and Gaul “the language differs but little.”
The common language referred to by Tacitus was probably not Celtic, but was similar to that spoken by the Belgae, who may have been a Germanic people, as implied by Caesar. In other words, a Germanic-type language could already have been indigenous to England at the time of the Roman invasion. In support of this inference, there is some recent lexical (vocabulary) evidence analysed by Cambridge geneticist Peter Forster and continental colleagues. They found that the date of the split between old English and continental Germanic languages goes much further back than the dark ages, and that English may have been a separate, fourth branch of the Germanic language before the Roman invasion.
Apart from the Belgian connection in the south, my analysis of the genetic evidence also shows that there were major Scandinavian incursions into northern and eastern Britain, from Shetland to Anglia, during the Neolithic period and before the Romans. These are consistent with the intense cultural interchanges across the North sea during the Neolithic and bronze age. Early Anglian dialects, such as found in the old English saga Beowulf, owe much of their vocabulary to Scandinavian languages. This is consistent with the fact that Beowulf was set in Denmark and Sweden and that the cultural affiliations of the early Anglian kingdoms, such as found in the Sutton Hoo boat burial, derive from Scandinavia.
A picture thus emerges of the dark-ages invasions of England and northeastern Britain as less like replacements than minority elite additions, akin to earlier and larger Neolithic intrusions from the same places. There were battles for dominance between chieftains, all of Germanic origin, each invader sharing much culturally with their newly conquered indigenous subjects.
So, based on the overall genetic perspective of the British, it seems that Celts, Belgians, Angles, Jutes, Saxons, Vikings and Normans were all immigrant minorities compared with the Basque pioneers, who first ventured into the empty, chilly lands so recently vacated by the great ice sheets.
The story originates with the clerical historians of the early dark ages. Gildas (6th century AD) and Bede (7th century) tell of Saxons and Angles invading over the 5th and 6th centuries. Gildas, in particular, sprinkles his tale with “rivers of blood” descriptions of Saxon massacres. And then there is the well-documented history of Anglian and Saxon kingdoms covering England for 500 years before the Norman invasion.
But who were those Ancient Britons left in England to be slaughtered when the legions left? The idea that the Celts were eradicated—culturally, linguistically and genetically—by invading Angles and Saxons derives from the idea of a previously uniformly Celtic English landscape. But the presence in Roman England of some Celtic personal and place-names doesn’t mean that all ancient Britons were Celts or Celtic-speaking.
The genocidal view was generated, like the Celtic myth, by historians and archaeologists over the last 200 years. With the swing in academic fashion against “migrationism” (seeing the spread of cultural influence as dependent on significant migrations) over the past couple of decades, archaeologists are now downplaying this story, although it remains a strong underlying perspective in history books.
Some geneticists still cling to the genocide story. Research by several genetics teams associated with University College London has concentrated in recent years on proving the wipeout view on the basis of similarities of male Y chromosome gene group frequency between Frisia/north Germany and England. One of the London groups attracted press attention in July by claiming that the close similarities were the result of genocide followed by a social-sexual apartheid that enhanced Anglo-Saxon reproductive success over Celtic.
The problem is that the English resemble in this way all the other countries of northwest Europe as well as the Frisians and Germans. Using the same method (principal components analysis, see note below), I have found greater similarities of this kind between the southern English and Belgians than the supposedly Anglo-Saxon homelands at the base of the Danish peninsula. These different regions could not all have been waiting their turn to commit genocide on the former Celtic population of England. The most likely reason for the genetic similarities between these neighbouring countries and England is that they all had similar prehistoric settlement histories.
When I looked at exact gene type matches between the British Isles and the continent, there were indeed specific matches between the continental Anglo-Saxon homelands and England, but these amounted to only 5 per cent of modern English male lines, rising to 15 per cent in parts of Norfolk where the Angles first settled. There were no such matches with Frisia, which tends to confirm a specific Anglo-Saxon event since Frisia is closer to England, so would be expected to have more matches.
When I examined dates of intrusive male gene lines to look for those coming in from northwest Europe during the past 3,000 years, there was a similarly low rate of immigration, by far the majority arriving in the Neolithic period. The English maternal genetic record (mtDNA) is consistent with this and contradicts the Anglo-Saxon wipeout story. English females almost completely lack the characteristic Saxon mtDNA marker type still found in the homeland of the Angles and Saxons. The conclusion is that there was an Anglo-Saxon invasion, but of a minority elite type, with no evidence of subsequent “sexual apartheid.”
The orthodox view is that the entire population of the British Isles, including England, was Celtic-speaking when Caesar invaded. But if that were the case, a modest Anglo-Saxon invasion is unlikely to have swept away all traces of Celtic language from the pre-existing population of England. Yet there are only half a dozen Celtic words in English, the rest being mainly Germanic, Norman or medieval Latin. One explanation is that England was not mainly Celtic-speaking before the Anglo-Saxons. Consider, for example, the near-total absence of Celtic inscriptions in England (outside Cornwall), although they are abundant in Ireland, Wales, Scotland and Brittany.
Who was here when the Romans came?
So who were the Britons inhabiting England at the time of the Roman invasion? The history of pre-Roman coins in southern Britain reveals an influence from Belgic Gaul. The tribes of England south of the Thames and along the south coast during Caesar’s time all had Belgic names or affiliations. Caesar tells us that these large intrusive settlements had replaced an earlier British population, which had retreated to the hinterland of southeast England. The latter may have been the large Celtic tribe, the Catuvellauni, situated in the home counties north of the Thames. Tacitus reported that between Britain and Gaul “the language differs but little.”
The common language referred to by Tacitus was probably not Celtic, but was similar to that spoken by the Belgae, who may have been a Germanic people, as implied by Caesar. In other words, a Germanic-type language could already have been indigenous to England at the time of the Roman invasion. In support of this inference, there is some recent lexical (vocabulary) evidence analysed by Cambridge geneticist Peter Forster and continental colleagues. They found that the date of the split between old English and continental Germanic languages goes much further back than the dark ages, and that English may have been a separate, fourth branch of the Germanic language before the Roman invasion.
Apart from the Belgian connection in the south, my analysis of the genetic evidence also shows that there were major Scandinavian incursions into northern and eastern Britain, from Shetland to Anglia, during the Neolithic period and before the Romans. These are consistent with the intense cultural interchanges across the North sea during the Neolithic and bronze age. Early Anglian dialects, such as found in the old English saga Beowulf, owe much of their vocabulary to Scandinavian languages. This is consistent with the fact that Beowulf was set in Denmark and Sweden and that the cultural affiliations of the early Anglian kingdoms, such as found in the Sutton Hoo boat burial, derive from Scandinavia.
A picture thus emerges of the dark-ages invasions of England and northeastern Britain as less like replacements than minority elite additions, akin to earlier and larger Neolithic intrusions from the same places. There were battles for dominance between chieftains, all of Germanic origin, each invader sharing much culturally with their newly conquered indigenous subjects.
So, based on the overall genetic perspective of the British, it seems that Celts, Belgians, Angles, Jutes, Saxons, Vikings and Normans were all immigrant minorities compared with the Basque pioneers, who first ventured into the empty, chilly lands so recently vacated by the great ice sheets.
Note: How does genetic tracking work?
The greatest advances in genetic tracing and measuring migrations over the past two decades have used samples from living populations to reconstruct the past. Such research goes back to the discovery of blood groups, but our Y-chromosomes and mitochondrial DNA are the most fruitful markers to study since they do not get mixed up at each generation. Study of mitochondrial DNA in the British goes back over a decade, and from 2000 to 2003 London-based researchers established a database of the geographically informative Y-chromosomes by systematic sampling throughout the British Isles. Most of these samples were collected from people living in small, long-established towns, whose grandparents had also lived there.
Two alternative methods of analysis are used. In the British Y-chromosome studies, the traditional approach of principal components analysis was used to compare similarities between whole sample populations. This method reduces complexity of genetic analysis by averaging the variation in frequencies of numerous genetic markers into a smaller number of parcels—the principal components—of decreasing statistical importance. The newer approach that I use, the phylogeographic method, follows individual genes rather than whole populations. The geographical distribution of individual gene lines is analysed with respect to their position on a gene tree, to reconstruct their origins, dates and routes of movement.
Two alternative methods of analysis are used. In the British Y-chromosome studies, the traditional approach of principal components analysis was used to compare similarities between whole sample populations. This method reduces complexity of genetic analysis by averaging the variation in frequencies of numerous genetic markers into a smaller number of parcels—the principal components—of decreasing statistical importance. The newer approach that I use, the phylogeographic method, follows individual genes rather than whole populations. The geographical distribution of individual gene lines is analysed with respect to their position on a gene tree, to reconstruct their origins, dates and routes of movement.
