Center of Genomics, Evolution and Medicine, Institute of Genomics, University of Tartu, Tartu 51010, Estonia.
Centre de Recherche sur la Biodiversité et l'Environnement, Université de Toulouse, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, Toulouse Institut National Polytechnique, Université Toulouse 3-Paul Sabatier, cedex 9, Toulouse 31062, France.
Proc Natl Acad Sci U S A. 2024 Jun 25;121(26):e2405889121. doi: 10.1073/pnas.2405889121. Epub 2024 Jun 18.
Neandertals and Denisovans, having inhabited distinct regions in Eurasia and possibly Oceania for over 200,000 y, experienced ample time to adapt to diverse environmental challenges these regions presented. Among present-day human populations, Papua New Guineans (PNG) stand out as one of the few carrying substantial amounts of both Neandertal and Denisovan DNA, a result of past admixture events with these archaic human groups. This study investigates the distribution of introgressed Denisovan and Neandertal DNA within two distinct PNG populations, residing in the highlands of Mt Wilhelm and the lowlands of Daru Island. These locations exhibit unique environmental features, some of which may parallel the challenges that archaic humans once confronted and adapted to. Our results show that PNG highlanders carry higher levels of Denisovan DNA compared to PNG lowlanders. Among the Denisovan-like haplotypes with higher frequencies in highlander populations, those exhibiting the greatest frequency difference compared to lowlander populations also demonstrate more pronounced differences in population frequencies than frequency-matched nonarchaic variants. Two of the five most highly differentiated of those haplotypes reside in genomic areas linked to brain development genes. Conversely, Denisovan-like haplotypes more frequent in lowlanders overlap with genes associated with immune response processes. Our findings suggest that Denisovan DNA has provided genetic variation associated with brain biology and immune response to PNG genomes, some of which might have facilitated adaptive processes to environmental challenges.
尼安德特人和丹尼索瓦人在欧亚大陆和可能的大洋洲的不同地区分别居住了超过 20 万年，有足够的时间来适应这些地区所带来的各种环境挑战。在现代人类群体中，巴布亚新几内亚人（PNG）是少数几个携带大量尼安德特人和丹尼索瓦人 DNA 的群体之一，这是过去与这些古老人类群体混合的结果。本研究调查了两个不同的 PNG 人群中，即居住在 Wilhelm 山高地和 Daru 岛低地的人群中，内侵的丹尼索瓦人和尼安德特人 DNA 的分布情况。这些地点具有独特的环境特征，其中一些可能与古老人类曾经面临和适应的挑战相似。我们的研究结果表明，与 PNG 低地人相比，PNG 高地人携带更高水平的丹尼索瓦人 DNA。在高地上人群中具有更高频率的丹尼索瓦人样单倍型中，与低地人群相比，频率差异最大的那些单倍型在人群频率上的差异比频率匹配的非古变体更为显著。这些高度分化的单倍型中有两个位于与大脑发育基因相关的基因组区域。相反，在低地人中更常见的丹尼索瓦人样单倍型与与免疫反应过程相关的基因重叠。我们的发现表明，丹尼索瓦人 DNA 为 PNG 基因组提供了与大脑生物学和免疫反应相关的遗传变异，其中一些可能促进了对环境挑战的适应过程。
