In a groundbreaking discovery, scientists have successfully sequenced the oldest known Homo sapiens DNA, providing new insights into the shared history between our species and Neanderthals. This remarkable research, published in the journal *Nature*, is centered around ancient remains found in a cave beneath a medieval castle in Ranis, Germany, which date back approximately 45,000 years.

The genomes, extracted from 13 bone fragments, belonged to six individuals, including a mother and daughter, as well as distant cousins. Intriguingly, analysis revealed that these early humans carried genetic evidence of Neanderthal ancestry, indicating that their ancestors likely interbred with Neanderthals around 80 generations prior, approximately 1,500 years earlier. This intermingling didn’t necessarily occur in the same location but marks a significant interaction point in human history.

Since the sequencing of the first Neanderthal genome in 2010, it has been established that early human populations interbred with Neanderthals, a revelation that continues to impact our understanding of human genetics today. However, determining the timeline, frequency, and specific locations of these interactions has proven challenging for researchers. Previous assumptions suggested early human-Neanderthal encounters likely occurred in the Middle East as Homo sapiens migrated out of Africa.

Expanding on the timeline, researchers conducted an extensive study published in *Science*, which analyzed data from 59 ancient humans along with genomes from 275 modern individuals. This study corroborated the findings from Ranis, suggesting that the bulk of Neanderthal ancestry present in modern humans can be traced back to a significant period of interbreeding that spanned approximately 50,500 to 43,500 years ago. This era coincides with the time just before Neanderthals began to vanish from the archaeological record.

At the peak of this historical interaction, which occurred around 47,000 years ago, early humans and Neanderthals coexisted, reproducing frequently. Subsequent analysis showed that specific genetic variants inherited from Neanderthals—comprising about 1% to 3% of modern human genomes—had a varying impact over time. Notably, some Neanderthal genes related to immune function remained beneficial, especially during the last ice age when humans faced a harsh environment.

The simultaneous publication of findings by multiple research teams highlighted how rare ancient genetic data can provide profound insights into human evolution and migration patterns. Tony Capra, an evolutionary geneticist not involved in the study, expressed that such research illustrates the significance of ancient genomes in refining our understanding of these complex interactions.

Additional insights into Neanderthal ancestry reveal uneven distributions of Neanderthal-derived genetic variants across the genome, with certain areas, termed “archaic deserts,” showing a lack of Neanderthal genes. This phenomenon likely arose quickly post-interbreeding—possibly within just 100 generations—due to the survival disadvantages posed by some Neanderthal traits, including potential hybrid infertility.

Examining the genomes reveals that the majority of Neanderthal variants associated with skin pigmentation, metabolism, and immune functions were beneficial as they adapted to harsh climates. Interestingly, individuals found in the Ranis cave had approximately 2.9% Neanderthal ancestry, mirroring what we see in most modern populations today.

This new timeline enhances our understanding of human migration, suggesting that significant movements out of Africa were largely completed by 43,500 years ago. Still, questions remain regarding variations in Neanderthal ancestry among contemporary populations, notably why East Asians exhibit higher levels of Neanderthal genes compared to Europeans.

The cave dwellers from Ranis represent some of the earliest Homo sapiens in Europe. Their lineage, however, appears to have vanished from history, leaving no direct ancestral traces in today's populations. This poses an intriguing question about the fate of various ancient human lineages, as other groups also faced extinction around 40,000 years ago, leading to speculation that the evolution of Homo sapiens may not have directly contributed to the decline of Neanderthals.

As researchers continue to study ancient remains from the Ranis site to unravel the life and diet of these early humans, it becomes clear that our history is rich and complex, often marked by not just survival and success, but also extinction and loss. The ongoing discovery of our genetic ties to Neanderthals paints a vivid picture of a shared, intertwined past that continues to shape our present.