Globally in 2022, there were an estimated 249 million malaria cases and 608,000 malaria deaths across 85 countries. Today, the majority of the disease is concentrated on the continent of Africa, which carries a disproportionately high share of cases. But it is also a serious and persistent threat in other areas—especially Southeast Asia, which has the second highest estimated malaria burden after Africa.
A new study, however, shows that was not the case for people living in ancient Asia. DNA analysis has revealed that ancient Eastern Arabia people developed resistance to malaria following the appearance of agriculture in the region around 5,000 ago.
In the study, published in Cell Genomics, a team of researchers from the University of Birmingham analyzed the remains of individuals from Tylos-period Bahrain (300 BCE to 600 CE) stored at the Bahrain National Museum. They extracted DNA from 25 people but—due to the age and hot climate—only samples from four individuals were suitable for sequencing. The results revealed the malaria-protective G6PD Mediterranean mutation in three of the four samples, suggesting that many in the region’s ancient populations enjoyed protection from the disease.
“According to our estimates, the G6PD Mediterranean mutation rose in frequency around 5,000 to 6,000 years ago, coinciding with the onset of agriculture in the region, which would have created ideal conditions for the proliferation of malaria,” said lead researcher Rui Martiniano from Liverpool John Moores University.
In the present day, among the populations examined, the G6PD mutation is detected at its peak frequency in the Emirates. Meanwhile, the study authors discovered that the ancestry of Tylos-period inhabitants of Bahrain comprises sources related to ancient groups from Anatolia, the Levant and Caucasus/Iran. Thus, the four Bahrain individuals examined were genetically more like present-day populations from the Levant and Iraq than Arabians.
Due to the poor DNA preservation conditions of the region, this is the first time scientists have been able to successfully sequence the genome of ancient people from Eastern Arabia. From a genetic perspective, the population history of Bahrain, and more generally of Arabia, has been severely understudied
“By obtaining the first ancient genomes from Eastern Arabia, we provide unprecedented insights into human history and disease progression in this region,” said study author Marc Haber, from the University of Birmingham Dubai. “This knowledge goes beyond historical understanding, providing predictive capabilities for disease susceptibility, spread, and treatment, thus promoting better health outcomes.”
Overall, the scientific finding of malaria adaptation agrees with archaeological and textual evidence that suggests malaria was historically endemic in Eastern Arabia, while the DNA ancestry of Tylos-period inhabitants of Bahrain corroborates archaeological evidence of interactions between Bahrain and neighboring regions.
“Our study also paves the way for future research that will shed light on human population movements in Arabia and other regions with harsh climates where it is difficult to find well-preserved sources of DNA,” said Salman Almahari, Director of Antiquities and Museums at the Bahrain Authority for Culture and Antiquities.