An intriguing new study sheds light on the potential role of Neanderthal blood types in their demise. Researchers at Aix-Marseille University conducted an analysis of ancient genomes, revealing that Neanderthals harbored a distinctive variant of the Rh blood group. This variant was incompatible with the blood types of early Homo sapiens and Denisovans, possibly leading to a condition known as hemolytic disease of the newborn (HDN). HDN, caused by Rh incompatibility, can result in severe anemia,