Genetic history of Europe

The genetic history of Europe tells us about the people who lived there long ago by looking at their DNA. It helps us understand how different groups of people mixed together over thousands of years. By studying DNA, scientists can learn about the ancestors of people living in Europe today and how they moved and changed over time.

Long ago, between 40 and 26 thousand years ago, early humans in Europe were part of a bigger group that also included people from parts of Asia. As the climate changed during the Last Glacial Maximum, people in different areas began to develop unique genetic traits.

After the ice age ended, around 20 thousand years ago, a group called west European hunter-gatherer (WHG) appeared in Western Europe. Later, during the Neolithic Revolution, farmers from places like Anatolia and the Caucasus moved into Europe, bringing new ways of living. During the European Bronze Age, people from the steppes of Pontic–Caspian steppes also arrived, mixing with local groups.

Today, people in Europe have different amounts of ancestry from these ancient groups. For example, farmers in Hungary had less WHG ancestry than those in Germany or Iberia. The genetic mix changed depending on where you lived. Over time, big movements like the Migration period and the decline of the Roman Empire helped shape the modern ethnic groups of Europe.

Scientists have only been able to study this genetic history since the late 20th century. It wasn’t until the 1990s and especially the 2000s that they could look at whole genomes from ancient people, giving us much clearer pictures of Europe’s past.

Prehistory

Neanderthals lived in Europe and western Asia for about 130,000 years, disappearing around 30,000 years ago. They were replaced by anatomically modern humans, who arrived in Europe around 40,000 years ago. It was discovered in 2010 that modern Eurasians have about 1.5–2.1% Neanderthal DNA on average.

Paleolithic

Modern humans began living in Europe during the Upper Paleolithic about 40,000 years ago. Some signs show the spread of the Aurignacian culture. The oldest known sample of a common European DNA group, called Haplogroup I, comes from Austria and dates back to about 30,000–31,000 years ago. At this time, a culture called the Gravettian also appeared.

Upper Paleolithic

It is thought that modern humans began to inhabit Europe during the Upper Paleolithic about 40,000 years ago. Some evidence shows the spread of the Aurignacian culture.

Last Glacial Maximum

The Last Glacial Maximum started around 30,000 years ago, causing Northern Europe to become empty of people. People took shelter in safe places called refugia, such as in Northern Iberia, Southwest France, the Balkans, Ukraine, and Italy. As glaciers melted around 16,000–13,000 years ago, people slowly moved back into Europe from these refugia.

Mesolithic

Mesolithic populations changed a lot due to being isolated for thousands of years, harsh conditions during the Last Glacial Maximum, and the quick spread from refugia at the start of the Mesolithic. By the end of the Last Glacial Maximum, familiar Eurasian looks had appeared.

Neolithic

The Neolithic started with farming, beginning in Southeast Europe about 10,000–3000 BCE and spreading into Northwest Europe between 4500 and 1700 BCE. Farming brought big economic and cultural changes to Europe and affected its genetic mix, especially with new genes coming from the Middle East into the Balkans.

Bronze Age

The Bronze Age brought long-distance trading networks, especially along the Atlantic Coast and Danube valley. There was migration from Norway to Orkney and Shetland, and from Germany to eastern England. Martin Richards estimated about 4% of mitochondrial DNA in Europe came from migrations during the Bronze Age.

Recent history

Expansions of the Roman Empire do not seem to have left clear genetic signs in Europe. Romance-speaking groups in the Balkans, such as Romanians, Aromanians, and Moldovans, genetically resemble nearby Greek and South Slavic peoples rather than modern Italians.

Genetics of modern European populations

Further information: Ethnic groups in Europe

Patrilineal studies

There are four main Y-chromosome DNA haplogroups that account for most of Europe's patrilineal descent.

• Haplogroup R1b is common in Europe, particularly in Western Europe. It is most common among Western Europeans and decreases in frequency with distance from the Atlantic.
• Haplogroup R1a is prevalent in much of Eastern and Central Europe. It increases in frequency as one moves east from Germany to Poland.
• Haplogroup I is found throughout Europe, with highest frequencies in the Nordic countries and the Balkan Peninsula.
• Haplogroup E1b1b was introduced into Europe by Neolithic farmers from the Middle East. It peaks in the southern Balkan region.

There are also several less prominent haplogroups found in certain areas of Europe.

Matrilineal studies

Studies of mitochondrial DNA haplogroups in Europe show less geographical patterning compared to Y DNA haplogroups. All Europeans are characterised by the predominance of haplogroups H, U and T. Genetic studies suggest some maternal gene flow to eastern Europe from eastern Asia or southern Siberia thousands of years ago. Maternal gene flow to Europe from sub-Saharan Africa began as early as 11,000 years ago.

European population sub-structure

Genetically, Europe is relatively homogeneous, but distinct sub-population patterns have been found, particularly along a southeast–northwest cline. Studies have revealed five major clinal patterns throughout Europe.

1. A cline of genes with highest frequencies in the Middle East, spreading to lowest levels northwest.
2. A cline of genes with highest frequencies among Finnish and Sami in the extreme north east.
3. A cline of genes with highest frequencies in the area of the lower Don and Volga rivers in southern Russia.
4. A cline of genes with highest frequencies in the Balkans and Southern Italy.
5. A cline of genes with highest frequencies in the Basque country.

Studies have also identified several distinct regions within Europe based on genetic differences. Finland shows the greatest distance to the rest of Europeans. The Baltic region, Central and Western Europe, and Italy also show distinct genetic patterns.

Autosomal DNA

East Asian ancestry is found at low frequency among some Europeans. Finns and Northeastern Russians have more than 12% East Asian ancestry. Studies show a consistent distinction between 'northern' and 'southern' European population groups. Most southern Europeans and most northern, western, central, and eastern Europeans show strong membership in these groups.

Two whole-genome studies of Eastern European populations showed genomic diversity not well represented in previous surveys. Within Russia, certain groups form a pole of genetic diversity distinct from other populations.

According to geneticist David Reich, Europeans descend from a mixture of four West-Eurasian ancestral components in varying degrees.

Siberian geneflow is found among several Uralic-speaking European ethnic groups. This Siberian component is linked to the dispersal of Uralic languages.

Like other Eurasian populations, ancestries are not homogenously distributed in European populations. WHG-related ancestries are highest in present-day individuals from the Baltic States, Belarus, Poland and Russia whilst EHG-related ancestries are highest in Finland and Estonia. Steppe-related ancestries are found in high levels in northern Europe.

Autosomal genetic distances (Fst) based on SNPs (2009)

The genetic distance between populations is often measured by Fixation index (Fst), based on genetic polymorphism data. Fst values range from 0 to 1, with higher values indicating greater genetic distance. These low Fst values suggest that most genetic variation is at the level of individuals within the same population group.

CEU – Utah residents with ancestry from Northern and Western Europe.

History of research

Further information: Population genetics

Classical genetic markers (by proxy)

One of the first scientists to study genes was Luigi Luca Cavalli-Sforza. He looked at tiny differences in proteins from blood, like ABO blood groups and others, to learn about DNA. This helped him see how different groups of people are related. He made charts to show these relationships and used special math to study big sets of data.

Direct DNA analysis

Further information: Genetic drift, Founder effect, and Population bottleneck

Today, scientists study DNA directly. They look at special parts of DNA passed only from mothers or fathers. This helps them learn about family history without mixing up the genes. However, these studies have some problems. Different scientists sometimes get different results, and it can be hard to know exactly when certain gene changes happened.

Studies of other parts of DNA give a fuller picture of a person’s genes, but they are harder to use for tracing long histories. All genetic studies have some limits and depend on how scientists interpret the data along with what we know from history and archaeology.