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| Beaker Culture Diffusion from Wikipedia |
Introduction
A recent paper entitled The
phylogenealogy of R-L21: four and a half millennia of expansion and
redistribution by Dr Flood, a former Principal Research Scientist at The Commonwealth
Scientific and Industrial Research Organisation, provides some interesting
insights into population changes in Britain and Ireland over a period of 4,500
years. Dr Flood argues that it is likely that the L21 genetic mutation
originated in the large Beaker colony in south-west Britain around 2,500 BC.
From there, it was carried by sea into north-west France, Ireland, north-west
Spain and the Middle Rhine, which today have a high incidence of L21, and into
Northern England and Scotland.
Around 100 BC, a second major R-L21 expansion was initiated in Ireland
and Scotland. Dr Flood suggests that this
is consistent with a collapse in the population of Ireland, followed by a rapid
expansion. It is thought that a severe weather event, famine and/or epidemic
occurred around this time. Famine, plague and war tend to be closely
associated. Ireland has suffered regular severe famines, as has Northern Europe
more generally.
Ireland’s isolation meant that there were many diseases to which the
Irish would not have acquired immunity. Examples of diseases that later
devastated the New World include smallpox, influenza, typhoid, yellow fever and
pertussis. Typically, these diseases wiped out 95% of newly exposed
populations.
Genetic Change
Every movement of people throughout history has
produced different challenges. The environment and the way that humans lived
meant that the genetic code of different branches of human beings mutated.
Within a population group those individuals with a certain mutation may have
greater survival rates than those without. Those without the mutation would die
at a faster rate and therefore the mutated gene spreads.
One reason many Africans are naturally resistant to
malaria is because 33,000 years ago the genetic structure of the African
population group changed (mutated). Because Europeans had already migrated out
of Africa, they did not carry this mutation and therefore many are not
resistant to malaria.
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| Reconstruction of Beaker Burial |
Beaker People
When the Beaker culture
extended to Britain and Ireland 4,500 years ago, it was brought by migrants who
almost completely replaced the existing inhabitants within a few hundred years.
The assumption that people today are directly descended from the people who
always lived in that same area no longer stands. Human populations have been
moving and mixing throughout history. These people have been credited with
introducing metalworking to Britain and spreading the Indo-European language
group.
In genetic terms, L21 is a major branch of the general Y-haplogroup R1b
that has dominated Western Europe since the early Bronze Age. About 37 per cent
of men in the British Isles are R-L21, and two-thirds of the Irish.
The Vikings
From about 793 AD Viking raiders from Scandinavia began to
assault the coastline of the British Isles. The Vikings occupied most of the
Scottish Isles and the Isle of Man initially and established large port
settlements at York, Dublin and along the south and east coast of Ireland. These
invaders took huge numbers of slaves to run their agricultural holdings, mostly
from now overpopulated Ireland and Scotland. It is reported that in a single
day, they took 1000 slaves from Dublin and their genetic inheritance is visible
today. It is thought that about 90 per cent of Nordic L21 men may be descended
from slaves taken in raids.
The Diaspora
From the 1840s, much of the population of Ireland, Scotland and Cornwall
went abroad as economic refugees. About 10 million Irish have emigrated and
today over 40 million North Americans claim Irish heritage. Following the
Highland Clearances and the dissolution of the Clans around 1750, the Scots
began to emigrate, and today around 50-million people identify as being of
Scots or Scots-Irish heritage, even though the population of Scotland is only
5.3 million.
The dating of the L21 mutation to around 2,500 has been supported by the
presence of Bell Beaker sites all over Britain and Ireland dating from before
2400 BC. For example, Cornwall has an abundance of Beaker sites including round
barrows and cairns, henges, stone circles and stone cist graves. The
Cornwall/Devon area was a major dissemination point for R-L21 and is likely to
have had the first large settlements in Britain.
Dalriada Overkingdom
The situation in Scotland is complicated by an invasion of the west
coast of Scotland by Irish Gaelic speakers who eventually seized power from the
Picts and gave Scotland its rulers, its Gaelic language and its name. Dr Flood
argues that the expansion of the mutation M222 in Scotland is the only clear
example of a concerted move by the Ui Neill group into Scotland, establishing
the Dalriada overkingdom of Argyll and Antrim.
Bottlenecks in our
genetic history
A population ‘bottleneck’ occurred around 74,000
years ago when the volcano that produced Lake Toba in Indonesia erupted and
ejected 2,800 cubic kilometres of volcanic ash. Sunlight was blocked out
through the entire Southeast Asia, South Asian and Arabian Peninsula and ash
formed a thick layer on the floor. Only 10,000 people are thought to have
survived this cataclysmic event, and these are now known as our distant
ancestors.
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| Example of Beaker Pottery |
Conclusion
The genetic mutation known as L21 originated in the large Beaker colony
in south-west Britain around 2,500 BC. The Beaker people expanded over a period
of a few hundred years, creating widely separated colonies in north-west
France, Ireland, north-west Spain, the Middle Rhine and into Northern England
and Scotland. These people have been credited with introducing metalworking to Britain
and spreading the Indo-European language group. The so-called
Bell Beaker, which gave the culture its name, may even have been used to drink
alcohol!
Around 100 BC, a second major R-L21 expansion was initiated in Ireland
and Scotland. Later invaders of Britain such as the Belgae, Saxons and Normans
had a British genetic mixture from the early Bronze Age. Researchers believe
that the human genome has been subject to irregular pruning including
considerable decreases in genetic diversity probably resulting from natural
disasters, epidemics or warfare. Perhaps we should raise a glass to these early
people – slainte!
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