Your Neanderthal DNA might actually be doing you some good

By Sarah Kaplan

The Washington Post

Most human genomes harbor small fragments of Neanderthal DNA, the legacy of prehistoric hanky-panky between our ancestors and their hominid cousins.

For the most part, that inheritance has been detrimental. Research suggests that as much as 10 percent of the human genome was inherited from archaic hominids other than Homo sapiens, but the majority of that material was weeded out by tens of thousands of years of natural selection. The DNA that does remain has been blamed for increasing risk of depression, Type 2 diabetes, Crohn’s disease, lupus, allergies, addiction and more.

But geneticists Fernando Racimo, Davide Marnetto and Emilia Huerta-Sanchez wanted to find evidence that our archaic inheritance actually does us some good. They went looking for instances of adaptive introgression – a phenomenon in which a newly introduced piece of genetic material is so beneficial that it quickly radiates out into the entire population.

ADVERTISEMENT
0 seconds of 0 secondsVolume 0%
Press shift question mark to access a list of keyboard shortcuts
00:00
00:00
00:00
 

“Nobody has yet done a systematic survey of adaptive introgression around the world,” said Racimo, a geneticist at the New York Genome Center and lead author on the study. “We were able to confirm some previous findings and report examples that have never been found before.”

Their results, published in the journal Molecular Biology and Evolution this week, suggest that humans have inherited helpful genetic variants associated with fat storage, respiration, skin pigmentation, liver function, immune response and keratin production.

These scraps of DNA come from both Neanderthals and Denisovans, another hominid known only from a few remains found in Russia. Tens of thousands of years after these species went extinct, their DNA may still be helping us survive the modern world.

Exactly why that’s happening is unclear. The statistical tool that Racimo and his colleagues developed was designed to scan thousands of human genomes from all over the world and pinpoint sections among certain populations that bore more resemblance to the DNA of archaic humans than that of other Homo sapiens – in other words, examples of adaptive introgression. Presumably, these variants spread throughout populations because they gave us some advantage. For example, a known instance of adaptive introgression that was confirmed by Racimo’s study can be found in Tibetans (whose genome is about 5 percent Denisovan): members of the mountain-dwelling society have a genetic variant that helps them breathe at high altitudes that is closely related to a Denisovan gene and is completely missing in the genomes of nearby Han Chinese individuals.

But most human traits come from a complex combination of genes, making it a lot more difficult to figure out exactly what makes the inherited genetic material beneficial.

“For a lot of these selection scans you can speculate based on the gene function but the actual adaptive reason is much harder to understand,” said Racimo, who was a PhD student at the University of California, Berkeley at the time of the study.

Racimo has his suspicions about the benefits of two of the genes he and his colleagues discovered: These variants are found in Native American, Eurasian and Denisovan populations and have to do with the production of fat tissue.

“We have an idea of what they are doing,” he said. But those findings are due to be published in another paper, so he couldn’t say more.

The main takeaway from the study, Racimo said, is that we owe more to our Neanderthal and Denisovan relatives than we think. For years, conventional wisdom about these archaic humans is that they were weaker, dumber and less evolutionarily fit than modern humans, and that’s why they died out. But Racimo believes that other hominid species could have actually helped humans.

“Archaic humans expanded out of Africa before modern humans, so they had a lot more time to adapt to the particular conditions of Europe and Asia,” he said. “A shortcut to adapt to these conditions, instead of waiting for the mutations to occur, is to obtain the genetic material from these archaic human groups who were established for a long time.”

For example, the genes associated with immunity may have helped Homo sapiens resist the new pathogens they encountered as they spread around the globe.

Lest you start feeling too warm and fuzzy about ancient human-Neanderthal relations, this issue of Molecular Biology and Evolution contains a study looking at another portion of our archaic inheritance: genital warts. According to a genetic analysis of HPV16, a strain of Human Papillomavirus, the disease was likely passed to modern humans who had sex with Neanderthals or Denisovans after leaving Africa.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Police Cmdr. Scott King answers questions about the Flock Safety license plate camera system on Thursday, June 5, 2025 in Mountlake Terrace, Washington. (Olivia Vanni / The Herald)
Mountlake Terrace approves Flock camera system after public pushback

The council approved the $54,000 license plate camera system agreement by a vote of 5-2.

Cascadia College Earth and Environmental Sciences Professor Midori Sakura looks in the surrounding trees for wildlife at the North Creek Wetlands on Wednesday, June 4, 2025 in Bothell, Washington. (Olivia Vanni / The Herald)
Cascadia College ecology students teach about the importance of wetlands

To wrap up the term, students took family and friends on a guided tour of the North Creek wetlands.

Community members gather for the dedication of the Oso Landslide Memorial following the ten-year remembrance of the slide on Friday, March 22, 2024, at the Oso Landslide Memorial in Oso, Washington. (Ryan Berry / The Herald)
The Daily Herald garners 6 awards from regional journalism competition

The awards recognize the best in journalism from media outlets across Alaska, Idaho, Montana, Oregon and Washington.

Edmonds Mayor Mike Rosen goes through an informational slideshow about the current budget situation in Edmonds during a roundtable event at the Edmonds Waterfront Center on Monday, April 7, 2025 in Edmonds, Washington. (Olivia Vanni / The Herald)
Edmonds mayor recommends $19M levy lid lift for November

The city’s biennial budget assumed a $6 million levy lid lift. The final levy amount is up to the City Council.

A firefighting helicopter carries a bucket of water from a nearby river to the Bolt Creek Fire on Saturday, Sep. 10, 2022, on U.S. 2 near Index, Washington. (Ryan Berry / The Herald)
How Snohomish County property owners can prepare for wildfire season

Clean your roofs, gutters and flammable material while completing a 5-foot-buffer around your house.

(City of Everett)
Everett’s possible new stadium has a possible price tag

City staff said a stadium could be built for $82 million, lower than previous estimates. Bonds and private investment would pay for most of it.

Jennifer Humelo, right, hugs Art Cass outside of Full Life Care Snohomish County on Wednesday, May 28, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
‘I’ll lose everything’: Snohomish County’s only adult day health center to close

Full Life Care in Everett, which supports adults with disabilities, will shut its doors July 19 due to state funding challenges.

Logo for news use featuring Snohomish County, Washington. 220118
Snohomish County Board of Health looking to fill vacancy

The county is accepting applications until the board seat is filled.

The Edmonds City Council gathers to discuss annexing into South County Fire on Tuesday, Dec. 3, 2024 in Edmonds, Washington. (Olivia Vanni / The Herald)
Edmonds could owe South County Fire nearly $6M for remainder of 2025 services

The city has paused payments to the authority while the two parties determine financial responsibility for the next seven months of service.

The Edmonds School District building on Friday, Feb. 14, 2025 in Lynnwood, Washington. (Olivia Vanni / The Herald)
State testing finds elevated levels of lead in Edmonds School District water

Eleven of the district’s 34 schools have been tested. About one-fifth of water outlets had lead levels of 5 or more parts per billion.

A man works on a balcony at the Cedar Pointe Apartments, a 255 apartment complex for seniors 55+, on Jan. 6, 2020, in Arlington, Washington. (Andy Bronson/The Herald)
Washington AG files complaint against owners of 3 SnoCo apartment complexes

The complaint alleges that owners engaged in unfair and deceptive practices. Vintage Housing disputes the allegations.

Stolen car crashes into Everett Mexican restaurant

Contrary to social media rumors, unmarked police units had nothing to do with a raid by ICE agents.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.