Sedimentary ancient DNA and the Palaeoecology of the Late Quaternary Extinctions

沉积古DNA与晚第四纪灭绝的古生态学

• 批准号: RGPIN-2020-06654
• 负责人: Poinar, Hendrik
• 金额: $ 4.44万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743597
• 关键词: Sedimentary; ancient; DNA; Palaeoecology; Late

Today, we are witnessing an acceleration of climate warming with potential environmental impacts unprecedented in the last 10,000 and perhaps even 125,000 years. Changes in artic and subarctic environments are largely exceeding those predicted, making the long-term effects of these changes on the macro (i.e. faunal, flora and insect community composition) and micro (i.e. bacteria, fungi and viruses) levels, a challenge to robustly model or predict. Here we propose to use ancient environmental DNA recovered from lake sediments and permafrost cores to closely track shifting ecological signatures in northwestern North America over the last ~25,000 years to disentangle long-term climate and ecological trends from the comparatively rapid peopling of the Americas. We will develop novel methodology and targeting strategies to enrich ecologically diagnostic palaeoenvironmental ancient biomolecules (DNA, proteins, RNA) from plants, fungi, animals, and microbiota to correlate with other multi-proxy indicators of ecological change, vertebrate restructuring, and archaeological mobility to holistically assess how and why terrestrial ecosystems trophically downscaled at end of the last ice age. Ancient biomolecules are transforming our ability to critically evaluate environmental and biotic change over intervals ranging from a few decades to hundreds of thousands of years. And there are few places on Earth where the need for such information is more vital than our warming Arctic, especially because the detection and assessment of trends now affecting the far north have potentially global significance. For this intent a baseline through previous climatic cycles (no anthropogenic forcing) is needed, against which change and its consequences can be reliably measured and compared. In this NSERC grant we intend to take our work an important step forward, by concentrating on developing and exploiting novel methodologies for fine-scale resolution of paleoecological change in well-calibrated, geologically significant sedimentary deposits (i.e. permafrost and lake sediments). We intend to work at all accessible levels, including not only floral and faunal studies but also previously untapped resources such as microbial community structure and pathways underlying active biogeochemical cycling. The short term-objectives outlined below will enable us to track, at unprecedented depth, how biodiversity was restructured in selected high-latitude and high-altitude areas of the Americas, through the Pleistocene/Holocene transition (~20,500-8,300 bp), an interval that witnessed with numerous megafaunal extinctions amid shifting influences from a changing climate, ecological reconfigurations, and ultimately anthropogenic forcing.

今天，我们目睹了气候变暖的加速，其潜在的环境影响是过去 10,000 年甚至 125,000 年来前所未有的。北极和亚北极环境的变化很大程度上超出了预测，使得这些变化对宏观（即动物、植物和昆虫群落组成）和微观（即细菌、真菌和病毒）水平的长期影响，对稳健地应对气候变化提出了挑战。模型或预测。在这里，我们建议利用从湖泊沉积物和永久冻土岩心中回收的古代环境 DNA 来密切跟踪过去约 25,000 年来北美西北部不断变化的生态特征，以理清长期气候和生态趋势与美洲相对快速的人口增长之间的关系。我们将开发新的方法和目标策略，以丰富来自植物、真菌、动物和微生物群的生态诊断古环境古代生物分子（DNA、蛋白质、RNA），与生态变化、脊椎动物重建和考古活动的其他多代理指标相关联，全面评估陆地生态系统在上一个冰河时代结束时如何以及为何营养规模缩小。古代生物分子正在改变我们批判性评估几十年到数十万年的环境和生物变化的能力。地球上很少有地方比我们变暖的北极更需要此类信息，特别是因为对目前影响远北地区的趋势的检测和评估具有潜在的全球意义。为此目的，需要通过先前的气候周期（无人为强迫）建立基线，根据该基线可以可靠地测量和比较变化及其后果。在这笔 NSERC 拨款中，我们打算将我们的工作向前迈出重要一步，重点开发和利用新方法，对经过良好校准、具有地质意义的沉积物（即永久冻土和湖泊沉积物）中的古生态变化进行精细解析。我们打算在所有可访问的层面上开展工作，不仅包括花卉和动物研究，还包括以前未开发的资源，例如微生物群落结构和活跃生物地球化学循环的途径。下面概述的短期目标将使我们能够以前所未有的深度追踪美洲选定的高纬度和高海拔地区的生物多样性是如何通过更新世/全新世过渡（~20,500-8,300 bp）进行重组的，在气候变化、生态重构和最终人为强迫的影响不断变化的过程中，见证了许多巨型动物的灭绝。