Genetic research: Residents of the Mani region in southern Greece represent one of the genetically oldest populations in Europe

A new genetic study has revealed that the inhabitants of the Inner Mani region, a remote region at the southernmost tip of Europe in the Peloponnese, Greece, represent one of the most genetically unique populations on the continent.

An international research group, including scientists From the Steinhardt Museum of Natural History at Tel Aviv University, Oxford University, Areopolis Health Center, European University Cyprus, FamilyTreeDNA and the National and Kapodistrian University of Athens, used genetic findings to show that the inhabitants of the Inner Mani region of southern Greece preserve an ancient genetic profile, predating the great population migrations that reshaped the Balkan region after the fall of the Roman Empire.

The new study is now published in the scientific journal Communications Biology..

Through high-resolution analysis of paternal (Y-chromosome) and maternal (mitochondrial DNA) lineages from the Inner Mani communities, the researchers show that the population is largely composed of descendants of local Greek-speaking groups that inhabited the region before the medieval period. Unlike many other Peloponnesian Greek populations, the inhabitants of the Inner Mani region remained isolated for hundreds if not thousands of years and there is little evidence of the absorption of later immigrant groups from more northern regions, such as Slavs, whose arrival changed the genetic makeup of large parts of southeastern Europe.

"The results of the study show that historical isolation left a clear genetic imprint," says the lead author, Dr. Leonidas-Romanos Dobranoglu, Senior Researcher at the Steinhardt Museum of Natural History at Tel Aviv University and Postdoctoral Fellow at the University of Oxford"The inhabitants of the Inner Mani region preserve a snapshot of the genetic landscape of southern Greece before the demographic changes of the early Middle Ages, and are the descendants of the people who built the unique megalithic structures found only in the Inner Mani region."

The results of the study indicate that the inhabitants of the Inner Mani region constitute a rare genetic "island" within mainland Greece, shaped by centuries of isolation.

"Although I am not a native of Mani, for me this was a very personal study. Thanks to the close collaboration with the community, we were able to resolve long-standing questions about the settlement patterns, origins and history of this area. We can now see how people shaped the Mani landscape, and how it shaped them back."

Participants from the Inner Mani region underwent high-resolution paternity (BigY) and maternal testing, which allowed their DNA to be compared with contemporary people from around the world, as well as with thousands of publicly available ancient DNA samples.

These comparisons allowed researchers to trace genetic relationships between the lineages of the inhabitants of the inner Mani region and other Mediterranean and European populations, and to understand how isolation, migration, and demographic revolutions shaped the genetic structure of the region over thousands of years.

Most of the paternal lineages originate from the Bronze Age, Iron Age, and Roman periods in Greece, with a notable absence of lineages from the Nomadic period.

Genetic patterns indicate a severe population contraction between the 4th and 7th centuries AD, followed by long-term genetic continuity, meaning that contemporary inhabitants of the Inner Mani region are descendants of a small number of ancestors who survived this period..

The new study finds that over 50% of modern-day men in the Inner Mani region are descended from a single male ancestor who lived in the 7th century AD. Such an extreme pattern points to a period when the local population was reduced to a very small number of families, likely due to epidemics, wars and regional instability, followed by expansion and persistence of the survivors over centuries.

Maternal lineages are more diverse, reflecting localized contacts led by women from neighboring regions and sometimes from more distant regions of the Mediterranean basin, including the Levant and North Africa.

The tribal affiliation according to the paternal lineage, central to the social organization of the inhabitants of this region, is consistent with the genetic evidence and confirms the many oral traditions about a common origin, some of which extend as far back as the 14th century, at least two hundred years earlier than previously believed.

The genetic patterns closely match the archaeological evidence, which includes the region's unique megalithic structures. This architectural style is represented by settlements built of massive stones, which likely originated in late antiquity and the early Middle Ages.

The findings provide a rare opportunity to understand the demography of Greece during the transition from late antiquity to the Middle Ages, a period for which genetic, archaeological, and historical data are extremely scarce.

The researchers also demonstrate how geography, social organization, and certain historical circumstances can preserve ancient genetic patterns in some areas long after they have changed elsewhere.. The research also allows us to learn about how small communities adapt and survive periods of demographic crisis.

for the scientific article

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