Researchers from the University of California, Berkeley, have presented new data on interspecies hybridization in the deep history of humanity. In addition to Neanderthals and Denisovans, modern humans inherited genetic material from two unknown archaic lineages.
One of them, tentatively named the "ghost" lineage, interbred with Homo sapiens in Africa over 50,000 years ago. This lineage diverged from the common tree about 800,000 years ago – around the same time that the paths of Neanderthals and Denisovans diverged. Its DNA constitutes about 1% of the genome of every person living today, regardless of origin.
The second, "super-archaic" lineage, existed even earlier – around 1.8 million years ago. It apparently interbred with Denisovans in Eurasia, and from them, fragments of DNA made their way to modern humans. Traces of this admixture are particularly noticeable in the populations of Oceania, where the Denisovan proportion is traditionally higher.
Scientists have developed a new computational method, TRACE, which reconstructs genealogical relationships from modern genomes without relying on ancient DNA. The application of this method allowed not only to detect these segments but also to show that both "ghostly" contributions together constitute about 2% of the modern human genome.
Many of these archaic fragments are concentrated in areas related to immunity and metabolism. This suggests that they may have helped ancient humans adapt to new pathogens and food sources. How exactly did these ancient genes influence our evolution?
The study was published on July 30, 2026, in the journal Science. The authors note that as genomic databases expand and new methods emerge, other hidden episodes of interspecies exchange may be identified.
