Scientists have recovered the oldest known Homo sapiens DNA from remains found in a cave under a medieval castle in Ranis, Germany.

The remains, which they date back to about 45,000 years agobelonged to six people, including a mother, a daughter and distant cousins. This discovery reveals important information about the history of early humans, especially about the interaction between them Homo sapiens and Neanderthals. The genes of these individuals bear evidence of Neanderthal inheritance, indicating that their ancestors interbred with Neanderthals about 1,500 years earlier than scientists had previously thought. These interactions probably occurred over a period of 7,000 years, peaking around 47,000 years ago.

The study enhances our understanding of interbreeding with Neanderthals, which has left traces in the genetic material of modern humans, contributing up to 1-3% of our DNA. Researchers now believe that the majority of this genetic exchange occurred between 50,500 and 43,500 years ago, challenging the previous view that these encounters occurred primarily in the Middle East. The findings show that early humans and Neanderthals lived together, interacted regularly and shared genetic traits, such as the immune system that helped humans survive in harsh conditions of the Ice Age.

However, the study also found regions of the human genome without Neanderthal DNA, called “ancient deserts.” These regions likely appeared due to negative effects from specific Neanderthal genes, such as birth defects or infertilitywhich would have reduced the chances of survival of the hybrid offspring. In particular, the X chromosome was one such “desert”, possibly linked to male sterility.

Unanswered questions

The people from Ranis had about 2.9% Neanderthal heritage, similar to people living today. This study provides a clearer dating of human migration, indicating that the main wave of migration out of Africa was largely complete by 43,500 years ago. However, questions remain open, such as why people in East Asia have more Neanderthal heritage than Europeans, or why Neanderthal genomes from this period show few traces of Homo sapiens DNA.

The people from Ranis were among the first Homo sapiens in Europe, with dark skin, dark hair and brown eyes, characteristics that reflect their recent origin from Africa. Although this small population eventually became extinct, their discovery sheds light on the complex web of human evolution, where survival was not always assured. The extinction of these early Homo sapiens and Neanderthals underscores the unpredictable nature of human history, which has been shaped by both successes and losses.