NEANDERTHAL GENOME

eanderthals—’ closest cousins—went extinct around 30,000 years ago. Yet some people possess genetic markers, and spread to parts of Europe and western Asia. After modern humans migrated out of Africa, researchers believe they encountered and interbred with Neanderthals in the Middle East around 60,000 years ago. As a result, modern humans of non-African descent share around 2 percent of their DNA with Neanderthals. Scientists are still learning how these genes manifest themselves. “Neanderthals contributed DNA to present-day people,” says Pääbo, “and this has physiological effects today, for example in immune defense, pain sensitivity, risk for miscarriages, and susceptibility to severe outcomes from COVID-19.