Neanderthals, often identified as unsightly grunting cavemen with massive foreheads and nearly nonexistent necks, are believed to have died out 40,000 years ago. Yet through their genome, they still have a say in the status of modern humans.
U.S. researchers shed new light on how these ancient ones still influence genes in modern humans, likely contributing to traits including height and the likelihood of having diseases such as lupus and schizophrenia.
"Even 50,000 years after the last human-Neanderthal mating, we can still see measurable impacts on gene expression," said University of Washington geneticist and study co-author Joshua Akey in a statement.
Neanderthal genetic variants have been previously linked to vulnerability to certain conditions, but scientists had difficulty knowing which mechanisms cause the said effects. Genetic instructions can be obtained from fossils, but they can no longer recover the RNA helping transmit the genetic information.
The team mined data from the Genotype-Tissue Expression (GTEx) Project, which looked for people carrying both Neanderthal and modern human versions of a gene, a version from each parent.
Akey, helping identify 12 Neanderthal genes associated with increased disease risk last year, said their results showed that Neanderthal DNA sequences still had an impact on how genes were turned on or off in humans today.
Even 50,000 years after the last interbreeding, the genetic influence remains "pervasive and important," Akey said.
The Neanderthal version of a gene known as ADAMTSL3, for instance, is tied to height and schizophrenia. Causal mutation, according to the study, was inherited from the Neanderthals.
Akey added that hybridization between Neanderthals and modern man is still a valid source of worry, as those ancient relics still result in greater genomic complexity. As a next endeavor, the team also seeks to investigate whether another hominid species, called Denisovans, contribute to gene expression.
The findings were discussed in the journal Cell.