Recent scientific discoveries have revealed that Neanderthal genes make up from 1 to 4% of the DNA of modern-day humans whose ancestors migrated out of Africa, but the question of how much those genes are still actively impacting human qualities has remained unresolved until now.
A multi-institutional research team led by Cornell University has developed a new set of computational genetic tools to investigate the genetic consequences of 50,000 years of interbreeding between non-African descendants of humans and Neanderthals. (The study only applies to descendants of humans who came from Africa before the Neanderthals died out, specifically those of European heritage.)
The researchers stated in eLife that some Neanderthal genes are responsible for various features in modern humans, including those with a significant influence on the immune system. Overall, however, the study shows that modern human genes are winning out over successive generations.
“Interestingly, we found that several of the identified genes involved in modern human immune, metabolic, and developmental systems might have influenced human evolution after the ancestors’ migration out of Africa,” said study co-lead author April (Xinzhu) Wei, an assistant professor of computational biology in the College of Arts and Sciences. “We have made our custom software available for free download and use by anyone interested in further research.”
UK Biobank data reveals Neanderthal genes impact modern human traits
The researchers investigated more than 235,000 genetic variations believed to have originated from Neanderthals using a large dataset from the UK Biobank containing genetic and phenotypic information from almost 300,000 British people of non-African heritage. They discovered that 4,303 of those DNA polymorphisms play a significant function in modern humans, influencing 47 separate genetic features such as a person’s inherent immune resistance to specific diseases.
Unlike prior research, which was unable to eliminate genes from modern human variants, the new study used more exact statistical approaches to focus on Neanderthal genes. While the study used a dataset of almost entirely white people living in the United Kingdom, the team’s new computational methods could pave the way for gleaning evolutionary insights from other large databases to delve deeper into archaic humans’ genetic influences on modern humans.
“For scientists studying human evolution interested in understanding how interbreeding with archaic humans tens of thousands of years ago still shapes the biology of many present-day humans, this study can fill in some of those blanks,” said senior investigator Sriram Sankararaman, an associate professor at the University of California, Los Angeles.
“More broadly, our findings can also provide new insights for evolutionary biologists looking at how the echoes of these types of events may have both beneficial and detrimental consequences,” he said.