Researchers at UC Berkeley have detected traces of DNA from an unidentified ancient population across five contemporary human groups. An examination of 503 genomes showed that this enigmatic ancestry accounted for an average of 0.49 to 1.1 percent of the genetic composition, with variations among the studied populations.<\/p>\n
The results, by Yulin Zhang and team, are elaborated in a peer-reviewed paper set to be published in Science in 2026. Importantly, the research did not include the sequencing of newly found bones. Instead, the scientists constructed ancestral family trees across chromosomes, investigating branches that extended far back into history.<\/p>\n
The research identified two separate signals of archaic lineage. The first unknown ancestry was inferred from the 503 genomes examined. Concurrently, a different analysis of 92 Oceanian genomes suggested the existence of a second, significantly older lineage. Importantly, no ancient genomes have been sequenced from these potential ancestral populations, meaning the study stands as an individual investigation rather than a broad-based agreement.<\/p>\n
The researchers utilized phased whole-genome sequences from the 1000 Genomes Project, facilitating the tracking of ancestry segments along chromosomes. The sample included 91 British genomes (Europe), 103 Han Chinese genomes (East Asia), 102 Indian Telugu genomes (South Asia), 108 Yoruba genomes (West Africa), and 99 Luhya genomes (East Africa), totaling 503 genomes.<\/p>\n
Remarkably, signs of the unidentified ancestry emerged in all five populations. In non-African groups, many segments were shared with sub-Saharan samples, whereas African groups maintained a broader array of unique segments. This indicates that gene flow transpired in Africa before extensive expansions disseminated ancestry beyond the continent. Notably, the percentages identified represent group averages, not uniform ratios in individuals.<\/p>\n
Chromosomes do not traverse history as entire units; recombination during gamete formation results in a mosaic of family trees. To capture this mosaic, geneticists use an ancestral recombination graph (ARG), which estimates shared ancestry across genomes.<\/p>\n
The team created TRACE (TRacking Archaic Contributions via ARG Estimation), which reconstructs these ancient contributions without requiring DNA from the archaic sources or unadmixed references. It identifies long-isolated populations by tracing long DNA branches and segments indicative of later interbreeding. The technique effectively differentiates between ancient divergence events and more recent gene flow occurrences.<\/p>\n
TRACE validated known patterns of Neanderthal and Denisovan ancestry in non-African samples. It also uncovered an unknown ancestry contributing 0.49 to 1.1 percent of the genomes of the examined populations. This lineage, displaying an average divergence from modern humans approximately 830,000 years ago, points to a historical mixing event predating the Neanderthal or Denisovan interactions.<\/p>\n
The second signal was identified by including 92 Oceanian genomes, where TRACE uncovered deep Denisovan regions, suggesting gene flow from an ancient lineage into Denisovans, potentially linked to Homo erectus. This “super-archaic” ancestry may have diverged from modern human lineages roughly 1.77 million years ago.<\/p>\n
While TRACE recovers known ancestries and effectively estimates genetic contributions, the outcomes are affected by thresholds for DNA segment length, mutation rates, and historical models. Various methods may yield differing estimates, emphasizing the intricacy of reconstructing ancient ancestries.<\/p>\n
By sharing their analytical workflows, the study opens avenues for further research integrating diverse populations and methodologies. Presenting captivating potentialities, this research bolsters the perception of human evolution as a complex interaction of separation, survival, and interbreeding, shedding light on populations that have long since faded from direct genetic records.<\/p>\n","protected":false},"excerpt":{"rendered":"
Researchers at UC Berkeley have detected traces of DNA from an unidentified ancient population across five contemporary human groups. An examination of 503 genomes showed that this enigmatic ancestry accounted for an average of 0.49 to 1.1 percent of the genetic composition, with variations among the studied populations. The results, by Yulin Zhang and team, […]<\/p>\n","protected":false},"author":1,"featured_media":375347,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"Default","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[179],"class_list":["post-375346","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-source-scienceblog-com"],"_links":{"self":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts\/375346","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=375346"}],"version-history":[{"count":0,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/posts\/375346\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=\/wp\/v2\/media\/375347"}],"wp:attachment":[{"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=375346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=375346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wolfscientific.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=375346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}