Reading the Levant through DNA

The Levant has long been one of the world's great crossroads, connecting Africa, Europe and Asia through thousands of years of migration, trade and conquest. Assyrians, Persians, Greeks, Romans, Arab dynasties, Crusaders and Ottomans all ruled parts of the Levant, leaving enduring marks on its languages, religions and cultures.

Conventional wisdom would suggest that centuries of conquest and migration produced a population in constant flux. Modern genetics tells a more complex story. While nearly every major civilization left a detectable genetic imprint, the region's underlying population has remained remarkably consistent, with successive migrations adding to an already established gene pool rather than replacing it.

That paradox has emerged through decades of research by geneticists studying both modern and ancient genomes, including Pierre Zalloua, Professor of Genetics at the University of Balamand, whose work draws on more than 22,000 DNA samples collected across the Middle East and North Africa.

“The biggest surprise when I studied the genetics of the Levant was how stable it has been,” Zalloua told The Beiruter.

 "Despite all the upheaval and all the population movements over thousands of years, there has been remarkable genetic continuity."

The authority of DNA

The findings arrive at a moment when genetics has moved well beyond university laboratories. Consumer DNA testing has become a global industry, while governments are investing unprecedented resources in large-scale genomic research. In June, the U.S. National Institutes of Health announced that its All of Us Research Program had become the world's largest integrated genomics and health database, containing genomic and clinical data from more than 747,000 participants, including over 535,000 whole-genome sequences.

At the same time, advances in next-generation sequencing have enabled scientists to recover DNA from human remains thousands of years old and compare those genomes directly with living populations. The technology has transformed population genetics into one of archaeology's fastest-growing fields, allowing researchers to reconstruct ancient migrations, population continuity and admixture, or the genetic mixing of populations, with unprecedented precision.

Those advances have transformed how scientists reconstruct the past while elevating DNA into an authoritative measure of ancestry and, increasingly, identity.

"There are two reasons why DNA has penetrated so deeply into our daily lives, and even into politics and identity," Zalloua said.

"The first is that DNA comes from science, and science gives it credibility. The second is that many people are not fully satisfied with their own identity. There is a void, and science can very easily fill that void because people trust scientific authority."

The concern, he argues, is therefore not the science itself, but the certainty often attached to genetic findings.

That distinction has taken on new significance, as DNA has entered political debates. In India, competing interpretations of ancient DNA have been drawn into debates over the origins of Indo-European languages and the historical foundations of Hindu nationalist narratives. In Europe and North America, a study published in Social Studies of Science found that users of Stormfront, a long-running white supremacist online forum, routinely reinterpreted consumer ancestry test results to preserve beliefs about racial purity even when the

genetic evidence contradicted their ideology.

Zalloua believes the renewed prominence of national identity, driven in part by large-scale migration, has made those debates even more consequential.

"People fear that their geography and their communities have been encroached upon by people coming from different backgrounds,” he said.

"We are now using DNA to tell people they belong to one ethnic group or another, which is becoming increasingly dangerous and divisive."

Tracing the Levant’s genetic history

The human genome contains a record of population history. As genetic mutations accumulate over generations, researchers can compare populations, estimate when groups diverged, identify episodes of migration and reconstruct relationships stretching back thousands of years.

When applied to the Levant, the genetic evidence challenged long-held assumptions about the region's demographic history.

Rather than repeated population replacement, the evidence suggests remarkable continuity accompanied by successive layers of migration. Persians, Greeks, Romans, Byzantines, Arab dynasties, Crusaders and Ottomans all left detectable genetic signatures. Collectively, however, those later populations account for only a relatively small share of the region's ancestry.

"The Byzantines, the Islamic expansions, the Crusaders and the Ottomans all left detectable genetic signatures," Zalloua said.

"But together, these later arrivals contribute no more than about 10% admixture to the original Levantine gene pool."

The conclusion is not that the Levant remained isolated. Quite the opposite. The region absorbed new populations for thousands of years while preserving much of its existing population.

The limits of DNA

If genetics has transformed our understanding of where populations came from, Zalloua argues it has also clarified what DNA cannot explain. Genetic ancestry is not the same as culture, nationality or identity, he said, and conflating the two risks asking science to answer questions it was never designed to resolve.

The distinction becomes particularly important in debates over indigeneity – a people's status as the original inhabitants of a particular place

Zalloua argues that indigeneity is ultimately a cultural relationship rather than a genetic one. Geography may matter, but it is only one element of belonging. Language, traditions, values and shared experience all shape identity in ways DNA cannot measure.

The same principle helps explain why geneticists can sometimes distinguish between Lebanon's religious communities even though religion itself is not inherited. Centuries of marriage within the same communities have left detectable genetic patterns among some Christian, Muslim and Druze populations. Those differences are the product of social and cultural practices over generations, not evidence that religion is encoded in DNA. In other words, culture can shape genetics over time, but genetics does not determine culture.

For Zalloua, genetics is most valuable when it helps reconstruct human history rather than define individual identity. It can reveal where populations came from, how they mixed and how societies evolved over thousands of years, but its purpose is to illuminate the past, not prescribe the present.

"DNA should be used to tell stories about ancestry and help trace where populations came from,” he said. 

"We tend to think and behave in certain ways because of our genes, but there is no such thing as genetic determinism. If you're searching for identity, don't look to DNA alone."