Recent research has provided new insights into the genetic interactions between Neanderthals and early Homo sapiens, helping us understand when and how these two species mixed. Neanderthals, or “Homo neanderthalensis,” were strong hominins with distinct physical features who lived in Europe, Asia, and the Middle East from around 430,000 years ago until their extinction about 39,000 years ago. Homo sapiens, originating in Africa around 300,000 years ago, came into contact with Neanderthals as they migrated into areas where Neanderthals lived. Two recent studies have refined the timeline of their interbreeding. One study, analyzing the oldest sequenced Homo sapiens DNA from remains in Germany and the Czech Republic, found gene flow between 49,000 and 45,000 years ago. Another study, examining both ancient and modern genomes, suggested a similar range of 50,500 to 43,500 years ago. These interactions likely happened over generations and left a lasting genetic impact on modern humans.

This interbreeding had significant biological and anthropological effects. Some Neanderthal genes helped Homo sapiens survive, particularly in areas like immune response, skin color, and metabolism. For example, a Neanderthal immune gene helps protect against coronaviruses. However, some harmful Neanderthal genes were lost over time. Today, about 1-2% of DNA in non-African populations comes from Neanderthals. The studies also show that early humans in Europe faced harsh conditions, with some populations dying out. These findings highlight the complex history of early humans and the lasting influence of Neanderthal genes.