Natural Sciences Active Updated Jun 19, 2026

Our ancient relatives, still in our genes

Ancient human relatives like the Denisovans and Neanderthals are turning out to still shape modern immune systems, sometimes raising disease risk and sometimes protecting against it, and the gaps in our genetic databases matter for health.

The story so far

  1. Jun 19, 2026 Latest

    Researchers catalogued more than 3,000 Denisovan genetic variants active in modern immune cells, with some Papua New Guinean populations carrying up to about 5 percent Denisovan DNA.

    Today Got Better

  2. Jun 14, 2026

    A study found the Denisovans, an ancient human relative we interbred with about 40,000 years ago, still influence part of the immune systems of people in Oceania.

    Today Got Better

  3. Jan 10, 2024

    Reading thousands of ancient genomes, Barrie and colleagues showed that the gene variants behind much of Europe's multiple sclerosis risk rode in with herders from the steppe about 5,000 years ago. Natural selection favored those same variants at the time, most likely because they hardened the immune system against the diseases of a herding life.

    Nature

  4. Feb 15, 2021

    A few months later the same pair found the other side of the ledger: a second Neanderthal stretch, on chromosome 12 near a group of antiviral genes, that lowers the risk of severe COVID-19 by around 22 percent. It is nearly absent in sub-Saharan Africa and common across Eurasia.

    PNAS

  5. Sep 30, 2020

    Hugo Zeberg and Svante Paabo showed that the single biggest genetic risk factor for severe COVID-19, a stretch of chromosome 3, was inherited from Neanderthals. About half of people in South Asia and one in six Europeans carry it.

    Nature

  6. Jan 7, 2016

    Dannemann, Andres and Kelso found that a cluster of three toll-like receptor genes, part of the body's first line of defense against bacteria and fungi, carries DNA inherited separately from Neanderthals and Denisovans. The archaic versions crank up the immune response, which came with a cost: a higher chance of allergies.

    American Journal of Human Genetics

  7. Aug 25, 2011

    Abi-Rached and colleagues traced a large share of modern immune-gene diversity back to our archaic cousins. Reading Neanderthal and Denisovan DNA, they showed that HLA immune types picked up through interbreeding, including one handed over by Denisovans in West Asia, now make up more than half the HLA alleles carried by people across Eurasia.

    Science

This story moves with the morning letter.

When this arc advances, the timeline above grows the same morning. One short, warm letter with the day's real progress in science, medicine and beyond. Free, every day.