Ghost DNA from Lost Humans Still Fights Infections

Tens of thousands of years after our ancestors interbred with Neanderthals and Denisovans, the genetic hand-me-downs from those extinct relatives are still doing biological work. Specifically, their DNA functions in the immune systems of people living across the Pacific today.

The team built their sample from 177 people across 12 Near Oceanian populations, spanning Papua New Guinea, the Bismarck Archipelago, and the Solomon Islands, and weighed those results against 1,284 previously published sequences from around the world. Despite harboring extraordinary diversity, these populations have been largely overlooked in global human genetic studies, which have skewed heavily toward people of European descent. Lead author Serena Tucci says that including more Oceanians in genomic datasets would fill a major gap in our picture of human evolution and improve the relevance of genetic research as it is increasingly used to guide medical treatments, helping reduce disparities in healthcare outcomes.

The data points to three distinct Denisovan introgression events into Oceanian populations, suggesting repeated contact rather than a single encounter. Researchers identified thousands of archaic variants that regulate gene activity, especially in immune and antiviral pathways. Tens of thousands of years later, this inherited DNA may still influence how these populations respond to viruses and their risk of autoimmune disease. The study also finds Denisovan ancestry affects skeletal development, evidence that these genetic contributions extend beyond immunity into core aspects of human biology.

If your genes are from Near Oceanic peoples, part of your immune system is running borrowed software from a species that went extinct roughly 50,000 years ago.

Read the full story at Yale News, June 11, 2026

Hot Take: In the West, ancestry seems more like a book than a tree. In Near Oceania, people carry their Denisovan ancestry as function, if not memory.