A recent analysis has shed light on the disparity in Neanderthal DNA within human populations in Europe and Asia, providing valuable insights into ancient genomes that hold potential medical significance today. Published in the Science Advances journal, this study enhances our understanding of the hereditary legacy from our distant species relatives, facilitated by a wealth of significant data.
The presence of Neanderthal DNA in contemporary human populations is attributed to interbreeding between our ancestors and Stone Age hominins, who became extinct roughly 40,000 years ago. Notably, East Asian populations exhibit a slightly higher concentration of Neanderthal DNA in their genetic makeup.
This distinction has long puzzled scientists, given the widespread discovery of Neanderthal remains across Europe and the Middle East but a scarcity of such evidence east of the Altai Mountains in Central Asia. As study co-author Mathias Currat, a senior genetics and evolution lecturer at the University of Geneva, noted, “So what’s puzzling is that in an area where we’ve never found any Neanderthal remains, there’s more Neanderthal DNA.”
Approximately 2 percent of the genetic composition of Eurasians comprises Neanderthal DNA, while in the case of East Asians, this proportion rises to around 4 percent, as Currat explained.
In their investigation, Currat and fellow researchers from the University of Geneva delved into the distribution of Neanderthal DNA inherited by humans over the past 40,000 years, aiming to unravel the mystery behind this difference.
According to the study’s findings, the distribution of Neanderthal DNA has not always displayed the pattern we observe today. In ancient genomes, older than 20,000 years, Stone Age Homo sapiens in Europe exhibited a slightly greater proportion of Neanderthal DNA than their counterparts in Asia.
The research suggests that the existing pattern of a higher percentage of Neanderthal ancestry in Asian populations compared to European populations developed at a later stage. This likely occurred during the Neolithic transition when farming supplanted hunting and gathering as the predominant way of life.
However, Currat noted that the specifics of how this transition unfolded in Asia remain unclear, largely due to a relative lack of data. The study encompassed 1,517 samples from Europe compared to 1,108 from Asia.