Overview
- The Science paper by Zhang, Biddanda, Moorjani and colleagues, published Thursday, July 30, 2026, reports that TRACE recovers known Neanderthal and Denisovan segments while detecting two previously uncharacterized archaic sources.
- One signal, called a 'ghost' lineage, appears in all modern populations and makes up about 0.5 to 1 percent of individual genomes according to the authors' analyses.
- A second 'super-archaic' signal, estimated to have split from our lineage roughly 1.8 million years ago, is detectable at very low levels in Oceanian genomes inside Denisovan-associated regions and averages about 0.002 percent there.
- TRACE works by reconstructing ancestral recombination graphs from hundreds of high-coverage modern genomes, and the team validated it in simulations and by recovering established archaic ancestry without using ancient reference genomes.
- The authors and outside experts stress caution: the findings need independent confirmation through other computational methods, broader and more diverse modern-genome sampling, and any recoverable ancient DNA, while the identified archaic segments show enrichment in immunity and metabolic loci that may have functional consequences.