{"id":2814,"date":"2025-02-24T14:59:22","date_gmt":"2025-02-24T13:59:22","guid":{"rendered":"https:\/\/jakobssonlab.iob.uu.se\/?p=2814"},"modified":"2025-02-24T14:59:22","modified_gmt":"2025-02-24T13:59:22","slug":"investigating-population-continuity-and-ghost-admixture-among-ancient-genomes","status":"publish","type":"post","link":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/2025\/02\/24\/investigating-population-continuity-and-ghost-admixture-among-ancient-genomes\/","title":{"rendered":"Investigating population continuity and ghost admixture among ancient genomes"},"content":{"rendered":"\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<div class=\"wp-block-group is-layout-grid wp-container-core-group-is-layout-099f7769 wp-block-group-is-layout-grid\">\n<figure class=\"wp-block-image size-large wp-container-content-8d08226a\"><img decoding=\"async\" src=\"https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2024\/05\/JamesMcKenna.jpg\" alt=\"\" class=\"wp-image-1410\" style=\"aspect-ratio:1;object-fit:cover\"\/><figcaption class=\"wp-element-caption\">James McKenna<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large wp-container-content-8d08226a\"><img decoding=\"async\" src=\"https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2024\/11\/20241112_124723-768x1024.jpg\" alt=\"Carolina Bernhardsson\" class=\"wp-image-2388\" style=\"aspect-ratio:1;object-fit:cover\"\/><figcaption class=\"wp-element-caption\">Carolina Bernhardsson<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"480\" height=\"600\" src=\"https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2025\/02\/MattiasJ-webb.jpg\" alt=\"\" class=\"wp-image-2815\" style=\"aspect-ratio:1;object-fit:cover\" srcset=\"https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2025\/02\/MattiasJ-webb.jpg 480w, https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2025\/02\/MattiasJ-webb-240x300.jpg 240w\" sizes=\"auto, (max-width: 480px) 100vw, 480px\" \/><figcaption class=\"wp-element-caption\">Mattias Jakobsson<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/jakobssonlab.iob.uu.se\/wp-content\/uploads\/2024\/11\/20241125_1508513-769x1024.jpg\" alt=\"Per Sj\u00f6din\" class=\"wp-image-2385\" style=\"aspect-ratio:1;object-fit:cover\"\/><figcaption class=\"wp-element-caption\">Per Sj\u00f6din<\/figcaption><\/figure>\n<\/div>\n\n\n\n<p><sup>Co-authors from the Jakobsson Lab.<\/sup><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-constrained wp-block-column-is-layout-constrained\" style=\"flex-basis:50%\">\n<p>The recent <a href=\"https:\/\/www.pivotscipub.com\/hpgg\/4\/3\/0009\" target=\"_blank\" rel=\"noreferrer noopener\">paper by McKenna, Bernhardsson, Waxham, Jakobsson and Sj\u00f6din (2024)<\/a> is published in HPGG.<\/p>\n<\/div>\n<\/div>\n\n\n\n<p><strong>Abstract<\/strong><\/p>\n\n\n\n<p>Ancient DNA (aDNA) can prove a valuable resource when investigating the evolutionary relationships between ancient and modern populations. Performing demographic inference using datasets that include aDNA samples however, requires statistical methods that explicitly account for the differences in drift expected among a temporally distributed sample. Such drift due to temporal structure can be challenging to discriminate from admixture from an unsampled, or \u201cghost\u201d, population, which can give rise to very similar summary statistics and confound methods commonly used in population genetics.<\/p>\n\n\n\n<p>Sequence data from ancient individuals also have unique characteristics, including short fragments, increased sequencing-error rates, and often limited genome-coverage that poses further challenges. Here, we present a novel and conceptually simple approach for assessing questions of population continuity among a temporally distributed sample. We note that conditional on heterozygote sites in an individual genome at a particular point in time, the mean proportion of derived variants at those sites in other individuals has different expectations forwards in time and backwards in time. The difference in these processes enables us to construct a statistic that can detect population continuity in a temporal sample of genomes. We show that the statistic is sensitive to historical admixture events from unsampled populations. Simulations are used to evaluate the power of this approach. We investigate a set of ancient genomes from Early Neolithic Scandinavia to assess levels of population continuity to an earlier Mesolithic individual.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Co-authors from the Jakobsson Lab. The recent paper by McKenna, Bernhardsson, Waxham, Jakobsson and Sj\u00f6din (2024) is published in HPGG. [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,18,11],"tags":[99,131,36,144,67],"class_list":["post-2814","post","type-post","status-publish","format-standard","hentry","category-news","category-publications","category-research","tag-admixture","tag-adna","tag-human-past","tag-palaeogenomics","tag-population"],"_links":{"self":[{"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/posts\/2814","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/comments?post=2814"}],"version-history":[{"count":1,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/posts\/2814\/revisions"}],"predecessor-version":[{"id":2816,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/posts\/2814\/revisions\/2816"}],"wp:attachment":[{"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/media?parent=2814"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/categories?post=2814"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jakobssonlab.iob.uu.se\/index.php\/wp-json\/wp\/v2\/tags?post=2814"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}