TRACE Finds 0.5%-1.1% Ghost DNA in 503 Genomes Across All Modern Populations
Updated
Updated · ZME Science · Aug 3
TRACE Finds 0.5%-1.1% Ghost DNA in 503 Genomes Across All Modern Populations
3 articles · Updated · ZME Science · Aug 3
Summary
Researchers applying TRACE to 503 genomes from five populations found an average 0.49% to 1.1% ancestry from an unknown archaic human lineage in every African and non-African group examined.
TRACE infers archaic introgression from ancestral recombination graphs rather than a reference genome, letting it flag deeply divergent DNA from unsampled populations; in simulations, it reached 92% accuracy with a false discovery rate below 0.25%.
The method also reproduced known patterns of archaic mixing, with more than 90% of detected Neanderthal segments and 70% of Denisovan segments overlapping established approaches.
Most ghost segments outside Africa were also found in sub-Saharan Africans, while African populations carried more unique variants, supporting a scenario in which the introgression happened before Homo sapiens expanded out of Africa.
The study also points to a separate super-archaic lineage that split about 1.8 million years ago, mixed with Denisovans, and later left a small trace in modern humans through them.