An international team of geneticists has sequenced the genomes of Sudanese residents, revealing unique aspects of their evolutionary history. The study found that Sudanese Copts—descendants of Christians who migrated from Egypt—acquired genetic protection against malaria within just a thousand years, thanks to intermixing with local tribes.

Sudan: A Crossroads of Peoples and Cultures

For millennia, Sudan has served as a vital corridor connecting Africa and the Middle East. This region has long been a melting pot of peoples, languages, and cultures. Yet, from a genetic perspective, Sudan remained largely unexplored: until recently, there were virtually no high-quality, complete genomes (WGS) available from Sudanese populations.

Genetic Resistance to Malaria

Malaria has always been one of the main threats to life in the Nile Valley. Over centuries of evolution, Sudan’s indigenous peoples developed genetic resistance to the disease. In contrast, the Coptic Christians who arrived from the north did not possess such protection.

The Course of the Study

The authors of the study, published in the journal PNAS, reconstructed the history of adaptation to malaria. Scientists sequenced 125 genomes at high coverage, collecting samples from representatives of five ethnic groups: Beja and Copts (speakers of Afroasiatic languages), Fur and Mahas (Nilo-Saharan languages), and the nomadic Fulani.

Using algorithms to analyze ancestral components, the researchers determined the origin of each DNA segment—whether from Europe, the Middle East, or various regions of Africa. Special attention was paid to areas with unusually high proportions of foreign DNA, indicating the action of natural selection.

Key Discoveries

The genetic analysis identified over a million new variations (SNPs) previously unknown to science. However, the most significant finding concerned the Sudanese Copts. Genetically, the Copts are close to Egyptians and Eurasians, but on the first chromosome, they have a segment where the proportion of local (Nilo-Saharan) DNA sharply rises to 30% (compared to an average of about 4% across the genome).

Detailed analysis showed that this segment contains the ACKR1 gene with the Duffy-null mutation. This mutation disables a receptor protein on the surface of red blood cells, which the malaria parasite (Plasmodium vivax) uses to enter blood cells. The Copts acquired this mutation by mixing with local Nubians approximately 1,000–1,500 years ago, during the flourishing of Christianity in Nubia.

Mathematical modeling indicated that the selection coefficient was 0.0996, meaning the beneficial gene spread rapidly through the Copt population—in just 45 generations.

Other Ethnic Groups

The study also shed light on the history of the Fulani. Their genome retains traces of ancient mixing between the peoples of West and North Africa, which occurred during the so-called “Green Sahara” period—a time when the present-day desert was covered with savannas and lakes, facilitating the migration of pastoralists.

Significance of the Study

The results show that human evolution is not just a matter of the distant past. A span of 1,500 years is quite recent by evolutionary biology standards, yet during this time, natural selection was able to alter the gene pool of an entire people and provide them with protection against a dangerous infection.