Study Traces Neanderthal DNA Influence in Modern Humans 47000 Years Later

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Research into human DNA from both prehistoric and modern sources reveals that Neanderthals and early modern humans interbred approximately 47,000 years ago, with this interbreeding lasting around 6,800 years. Neanderthals, who inhabited Europe and Asia, and Homo sapiens, who evolved in Africa, began to mix when modern humans migrated out of Africa. This interbreeding contributed 1% to 2% of Neanderthal DNA to the genomes of contemporary humans outside Africa.

To understand the timing and extent of this genetic exchange, scientists analyzed over 300 human genomes, including samples from individuals living between 2,200 and 45,000 years ago and present-day humans. The analysis indicated a significant interbreeding event occurred around 47,000 years ago, likely in western Asia, where Africa connected with Eurasia before modern humans dispersed globally.

The study also examined how Neanderthal DNA has persisted in modern humans. It found that genes related to skin colour, metabolism, and immune responses, which provided advantages, were retained, while less beneficial genes were quickly phased out. Initially, Neanderthal DNA made up more than 5% of the modern human genome, indicating that approximately one in twenty ancestors of early modern humans was a Neanderthal.

Moreover, evidence suggests that while interbreeding did occur, it might not have been reciprocal, with Neanderthals possibly not integrating modern human DNA into their genomes. This research enhances our understanding of human migration patterns and interactions with Neanderthals, influencing theories about early human dispersal and the genetic legacy of these ancient encounters.