Scientific research articles in journals such as Science and Nature

Neanderthal-Human Interbreeding Occurred 47,000 Years Ago, Lasted 7,000 Years

Dec 12, 2024, 07:08 PM

Recent research has provided new insights into the interbreeding between modern humans (Homo sapiens) and Neanderthals, pinpointing a significant period of gene flow between 50,500 and 43,500 years ago. This interbreeding event, which lasted approximately 7,000 years, has left a genetic imprint on all non-African populations today, with East Asians carrying about 20% more Neanderthal DNA than Europeans and West Asians. The studies, published in Science and Nature, utilized the DNA from ancient and modern humans to estimate the timing of this genetic exchange, suggesting that the diversification of humans outside Africa began after this period. The research also highlights the complexity of the early human migration out of Africa, with evidence of multiple waves of migration and extinction events. Notably, the oldest modern human genomes sequenced, from individuals who lived between 42,000 and 49,000 years ago in Ranis, Germany, and Zlatý kůň, Czechia, show that these early humans already carried Neanderthal ancestry, indicating that the interbreeding occurred shortly after Homo sapiens left Africa. The genetic analysis revealed that Neanderthal genes related to the immune system, skin pigmentation, and metabolism were retained in modern humans, while regions devoid of Neanderthal DNA, known as genetic deserts, developed rapidly, suggesting that some Neanderthal gene variants were detrimental. These findings challenge previous assumptions about the straightforward success of Homo sapiens in Europe and suggest a more nuanced history of human evolution.