Genetic data show mainly men migrated from the Pontic steppe to Europe 5,000 years ago

February 21, 2017

A new study, looking at the sex-specifically inherited X chromosome of prehistoric human remains, shows that hardly any women took part in the extensive migration from the Pontic-Caspian Steppe approximately 5,000 years ago. The great migration that brought farming practices to Europe 4,000 years earlier, on the other hand, consisted of both women and men. The difference in sex bias suggests that different social and cultural processes drove the two migrations.

Genetic data suggest that modern European ancestry represents a mosaic of ancestral contributions from multiple waves of prehistoric migration events. Recent studies of genomic variation in prehistoric have demonstrated that two mass migration events are particularly important to understanding European prehistory: the Neolithic spread of agriculture from Anatolia starting around 9,000 years ago, and migration from the Pontic-Caspian Steppe around 5,000 years ago. These migrations are coincident with large social, cultural, and linguistic changes, and each has been inferred to have replaced more than half of the contemporaneous gene pool of resident Central Europeans.

Dramatic events in human prehistory can be investigated using patterns of genetic variation among the people that lived in those times. In particular, studies of differing female and male demographic histories on the basis of ancient genomes can provide information about complexities of social structures and cultural interactions in prehistoric populations.

Researchers from Uppsala and Stanford University investigated the genetic ancestry on the sex-specifically inherited X chromosome and the autosomes in 20 early Neolithic and 16 Late Neolithic/Bronze Age human remains. Contrary to previous hypotheses suggesting patrilocality (social system in which a family resides near the man's parents) of many agricultural populations, they found no evidence of sex-biased admixture during the migration that spread farming across Europe during the early Neolithic.

For later migrations from the Pontic steppe during the early Bronze Age, however, we find a dramatic male bias. There are simply too few X-chromosomes from the migrants, which points to around ten migrating males for every migrating female, says Mattias Jakobsson, professor of Genetics at the Department of Organismal Biology, Uppsala University.

The research group found evidence of ongoing, primarily male, migration from the steppe to central Europe over a period of multiple generations, with a level of sex bias that excludes a pulse migration during a single generation.

The contrasting patterns of sex-specific migration during these two migrations suggest a view of differing cultural histories in which the Neolithic transition was driven by mass migration of both males and females in roughly equal numbers—perhaps whole families—whereas the later Bronze Age migration and cultural shift were instead driven by male .

Explore further: Baltic hunter-gatherers began farming without influence of migration, ancient DNA suggests

More information: "Ancient X chromosomes reveal contrasting sex bias in Neolithic and Bronze Age Eurasian migrations," PNAS, DOI: 10.1073/pnas.1616392114 , http://www.pnas.org/content/early/2017/02/17/1616392114.abstract

Related Stories

1,000 prehistoric individuals to be genetically mapped

October 7, 2016

A new research project, '1,000 Ancient Genomes', seeks to map the genetic variation among 1,000 prehistoric individuals who lived in Europe and Asia between 1,000 and 50,000 years ago. This data will help researchers give ...

First ancient Irish human genomes sequenced

December 28, 2015

A team of geneticists from Trinity College Dublin and archaeologists from Queen's University Belfast has sequenced the first genomes from ancient Irish humans, and the information buried within is already answering pivotal ...

Recommended for you

Upward mobility has fallen sharply in US: study

April 24, 2017

In a sign of the fading American Dream, 92 percent of children born in 1940 earned more than their parents, but only half of those born in 1984 can say the same, researchers said Monday.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Osiris1
not rated yet Feb 22, 2017
The earliest migration in the article... approx 7000 BC maybe refugees and/or diaspora from the flooding of the old 'Black Lake' when the Bosporous 'dam' was overtopped and the salty waters of the Mediterranean flooded the area, creating the present 'Black Sea'. Difficult to do archaeology there because of politics and religion as no one wants their faith possibly stepped on by facts. In any case, the Black Sea is an extremely challenging environment of greater technical difficulty than most present day science can overcome. Perhaps it is better this way, for the secrets those depths hold are now safe from religious wackos and political wackos alike. Perhaps after they all kill each other off or die of old age, a new day of intellectual and secular freedom will arise in the area. It CAN arrive, as one only needs look back to the era of good feeling among south Slavic groups in the 1920's that created the state of Yugoslavia out of the ruins of Austro-Hungary after WWI.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.