Black Death may have caused convergent evolution in the immune systems of two distinct populations

(Medical Xpress)—Throughout human history, our immune systems have evolved in response to infectious diseases. People with genes that provide resistance to specific pathogens are more likely to survive infection and transmit those genes to future generations than people without these resistant genes. To gain a better understanding of how disease affects the evolution of our immune systems, Mihai Netea of Radboud University Nijmegen Medical Centre in the Netherlands and his colleagues studied two genetically distinct ethnic groups, European Romanians and Rroma, both of which lived in Romania during the time of the Black Death, or Black Plague. The researchers found that both groups harbor genes that provide resistance to the plague, and that these genes do not exist in populations from North India, the original home of the Rroma. This indicates that the immune systems of European Romanians and Rroma evolved convergently in response to the disease. The study appears in the Proceedings of the National Academy of Sciences.