4000 genomes from 40,000 years: Tracing Neanderthal DNA in Eurasians
Neanderthal genes can be found in the DNA of certain modern humans.
Genetic studies have revealed interbreeding between modern humans (Homo sapiens) and Neanderthals (Homo neanderthalensis) tens of thousands of years ago.
Interbreeding happened around 40,000 years ago when Homo sapiens from Africa traveled to the western portions of the Eurasian continent.
Neanderthals had already inhabited the western Eurasian continent for thousands of years before this encounter.
A study led by the University of Geneva has examined the distribution of the Neanderthal-inherited DNA segments within the genomes of humans.
This new research might help us better grasp the shared history of these two species.
Examination of 4,000 genomes
The modern Eurasian populations have some two percent of their DNA derived from Neanderthal ancestors.
The recent study highlights that this minor Neanderthal DNA component exhibits slight variations across different Eurasian regions. Neanderthal DNA appears more abundant in Asian people’s genomes than in European populations.
“In the case of Sapiens and Neanderthals, the hypothesis is that the further one moves away from Africa, Homo sapiens’ point of origin, the greater the proportion of DNA from Neanderthal, a population mainly located in Europe,” noted the press release.
The team investigated this theory with the help of a comprehensive genome database provided by Harvard Medical School. The database contains almost 4,000 genomes from people living in Eurasia for the last 40,000 years. This study mainly examined the genomes of European populations.
The key genetic variations
Statistical analyses of the genomes revealed exciting insights about the genetic variation.
It found that when Homo sapiens left Africa, Paleolithic hunter-gatherers in Europe had somewhat more Neanderthal DNA than those in Asia.
As the Neolithic era began 10,000 to 5,000 years ago, there was a drop in Neanderthal DNA in European populations, which was lower than in Asian ones. This period represents the shift from the hunter-gatherer to the agricultural lifestyle.
This decline coincided with the arrival of the first farmers from Anatolia (Turkey’s western peninsula) and the Aegean area, who carried less Neanderthal DNA. Their intermixing with European populations further decreased the prevalence of Neanderthal DNA in European genomes.
“We are beginning to have enough data to describe more and more precisely the percentage of DNA of Neanderthal origin in the genome of Sapiens at certain periods of prehistory. Our work can, therefore, serve as a reference for future studies to more easily detect genetic profiles that deviate from the average and might, therefore, disclose an advantageous or disadvantageous effect,’’ concluded Mathias Currat, one of the study’s authors.
Studying early human genes could provide insights into our evolutionary history, helping experts trace the origins and development of the human species.
Source: Interesting Engineering
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4000 genomes from 40,000 years: Tracing Neanderthal DNA in Eurasians