A remote peninsula in southern Greece may hold a living genetic link to the ancient Mediterranean world. A new study in Communications Biology examined DNA from people in the Deep Mani region of the Peloponnese. Scientists from the University of Oxford, along with partners in Greece and Cyprus, compared DNA from Deep Mani residents to large modern genetic databases and thousands of ancient DNA samples.
The researchers found that many locals have strong genetic ties to Bronze Age and Classical-era Greeks. While most of southeastern Europe saw major population changes in the Medieval period, the community of Deep Mani seems to have retained older paternal lineages from before those migrations.
An Isolated Peninsula
The Mani Peninsula extends south into the Mediterranean Sea and is known for its steep landscape and hard-to-reach location. For a long time, historians and anthropologists have thought that this geography limited outside influence in the area. The new genetic findings support this theory, at least for male ancestry.
The researchers used Y-chromosome markers to trace male ancestry and mitochondrial DNA to trace maternal lines. They compared these genetic patterns with ancient Bronze Age and Classical Age Greek genomes and with modern groups living across the Balkans.
The Y-chromosome results told a unique story. Many male lineages in Deep Mani were very similar to those in ancient southern Greek individuals. Nearby regions, however, showed greater genetic influence from later Medieval migrations, such as the Slavic expansions that impacted the genetic diversity of mainland Greece. This means that the genetic profile of communities in Deep Mani has stayed closer to its ancient roots than those of neighboring areas.
Separate Patterns in Genetic Evidence
The female genetic evidence from the study, however, points to contact with individuals from outside communities. Scientists used mitochondrial DNA samples to trace maternal ancestry in women. The lineages of females living in Deep Mani were more diverse than those of males and showed evidence of mixing with external populations over many centuries. This implies that women from other regions eventually joined Maniot communities through marriage or migration.
This pattern of stable paternal ancestry with a more diverse maternal ancestry is also common in other isolated regions. It highlights how social customs and geographic factors can play a role in shaping genetic history. Although Deep Mani was not completely inaccessible, its isolated geography and strong community ties likely influenced the extent of outside contact.
Medieval Transformations
A majority of Greece experienced significant population changes between late antiquity and the Medieval period. Both archaeological and historical records show waves of migration, shifts in political control, and people moving across the Balkans.
Genetic studies of other mainland Greek individuals often show clear signs of these changes. However, these demographic pressures did not impact the people of Deep Mani in the same way. The researchers suggest that limited access to the peninsula hindered the movement of new male lineages into the region. Over time, this geographic barrier may have helped preserve ancient male lineages in the Deep Mani community, even as neighboring areas became more genetically diverse.
“Deep Maniots preserve a snapshot of the genetic landscape of southern Greece before the demographic upheavals of the early Middle Ages and likely descend from the same people who constructed the unique type of megalithic buildings that are found exclusively in Deep Mani,” said lead author Dr. Leonidas-Romanos Davranoglou.
Insight Beyond Historical Records
While historical records describe Medieval population movements, this research provides a closer look at how those changes impacted communities in different ways. Some regions underwent major changes, while others retained their original genetic roots.
This genetic continuity provides another way to understand the influence of factors such as geography, political change, and social customs. In Deep Mani, the landscape acted as a long-term filter. Not a complete barrier, but enough to help preserve paternal genetic lines that trace back thousands of years.
“The community was engaged in every stage of the research – from planning our sampling strategy and helping their fellow Deep Maniots interpret the results of our research. This study gives a voice to the stories of our ancestors. As a Deep Maniot myself, I wish my forefathers could have witnessed many of their oral histories being verified through genetics. It is a moment of immense pride and connection to our history,” said co-author Dr. Anargyros Mariolis.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds a Master of Business Administration, a Bachelor of Science in Business Administration, and a Data Analytics certification. His work combines analytical training with a focus on emerging science, aerospace, and astronomical research.