Sedimentary ancient DNA from Kronotsky Peninsula: how sea ice, salinity and insolation dynamics have shaped diatom composition and richness over the past 20,000 years

This article explores the conceptual and cultural implications of using pathogen ancient DNA (aDNA) collected in archaeological contexts to understand the past. More specifically, it examines ancient pathogen genomics as a way of conceptualizing multispecies entanglements. The analysis focuses on the 2018 sequencing of Borrelia recurrentis bacteria retrieved from a medieval graveyard in Oslo, Norway. B. recurrentis is associated with louse-borne relapsing fever (LBRF), known to have killed several million people in Europe during the past millennium, and it is still encountered in parts of East Africa. The article demonstrates that while aDNA research often foregrounds multispecies entanglements, its epistemic tools cannot easily address the ontological blurriness of pathogens and their embeddedness in vibrant material processes. The article draws on feminist posthumanities work on microbes and materiality to highlight conceptual openings that a theorization of ancient pathogens could engender.

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Sea ice protists in arctic marine sedaDNA records: origins, diversity, and vertical export of DNA from the sea surface to the seafloor

10.5194/egusphere-egu21-8030 ◽

2021 ◽

Author(s):

Sara Harðardóttir ◽

Connie Lovejoy ◽

Marit-Solveig Seidenkrantz ◽

Sofia Ribeiro

Keyword(s):

Sea Ice ◽

Ocean Circulation ◽

Ancient Dna ◽

Genetic Material ◽

Amplicon Sequencing ◽

Arctic Sea Ice ◽

The Arctic ◽

Gene Copy ◽

Marine Biodiversity ◽

Vertical Export

Arctic sea ice is declining at an unprecedented pace as the Arctic Ocean heads towards ice-free summers within the next few decades. Because of the role of sea ice in the Earth System such as ocean circulation and ecosystem functioning, reconstructing its past variability is of great importance providing insight into past climate patterns and future climate scenarios. Today, much of our knowledge of past sea-ice variability derives from a relatively few microfossil and biogeochemical tracers, which have limitations, such as preservation biases and low taxonomic resolution. Marine sedimentary ancient DNA (marine sedaDNA) has the potential to capture more of the arctic marine biodiversity compared to other approaches. However, little is known about how well past communities are represented in marine sedaDNA. The transport and fate of DNA derived from sea-ice associated organisms, from surface waters to the seafloor and its eventual incorporation into marine sediment records is poorly understood. &#160;Here, we present results from a study applying a combination of methods to examine modern and ancient DNA to material collected along the Northeast Greenland Shelf. We characterized the vertical export of genetic material by amplicon sequencing the hyper-variable V4 region of the 18S rDNA at three water depths, in surface sediments, and in a dated sediment core.&#160; The amplicon sequencing approach, as currently applied, includes some limitations for quantitative reconstructions of past changes such as primer competition, PCR errors, and variation of gene copy numbers across different taxa. For these reasons we quantified amplicons from a single species, the circum-polar sea ice dinoflagellate Polarella glacialis in the marine sedaDNA, using digital droplet PCR. The results will increase our understanding on the taphonomy of DNA in sea ice environments, how sedimentation differs among taxonomic groups, and provide indications to potentially useful marine sedaDNA-based proxies for climate and environmental reconstructions.

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The Paleoepidemiology of American Trypasonomiasis (Chagas disease)

Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale ◽

10.4081/jbr.2005.10100 ◽

1970 ◽

Vol 80 (1) ◽

Author(s):

Wilmar Salo ◽

William C. Auferheide ◽

Michael Madden ◽

John Streitz ◽

Jane Buikstra ◽

...

Keyword(s):

Soft Tissue ◽

Ancient Dna ◽

Academic Discipline ◽

Atacama Desert ◽

Geographic Area ◽

Northern Chile ◽

Kinetoplast Dna ◽

Testing Hypotheses ◽

The Past ◽

Tissue Specimens

Ancient DNA methodology was applied to extract and amplify a segment of kinetoplast DNA of Trypanosoma cruzi in soft tissue specimens from about 300 spontaneously mummified human bodies from the Atacama Desert in northern Chile and southern Peru. A DNA probe was then employed to hybridize with the amplicon. Results indicate that about 41% of the population in that geographic area were infected with the trypanosome over the past 9000 years. The epidemiological implications of these findings are discussed. It is also emphasized that this and several other paleoepidemiological studies in progress have established that population-study cohorts of mummies now can generate statistically valid paleoepidemiological investigations capable of testing hypotheses. These reflect the maturation of the academic discipline of the scientific study of mummies.

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Unlocking the Past on the “Bases” of Ancient DNA

Cell ◽

10.1016/j.cell.2016.06.053 ◽

2016 ◽

Vol 166 (2) ◽

pp. 259-261

Keyword(s):

Ancient Dna ◽

The Past

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Exceptional retreat of Novaya Zemlya's marine-terminating outlet glaciers between 2000 and 2013

10.5194/tc-2017-32 ◽

2017 ◽

Author(s):

J. Rachel Carr ◽

Heather Bell ◽

Rebecca Killick ◽

Tom Holt

Keyword(s):

Sea Ice ◽

Sea Level Rise ◽

Sea Level ◽

Remotely Sensed ◽

Glacier Retreat ◽

Remotely Sensed Data ◽

Novaya Zemlya ◽

The Past ◽

Air Temperatures ◽

The Impact

Abstract. Novaya Zemlya (NVZ) has experienced rapid ice loss and accelerated marine-terminating glacier retreat during the past two decades. However, it is unknown whether this retreat is exceptional longer-term and/or whether it has persisted since 2010. Investigating this is vital, as dynamic thinning may contribute substantially to ice loss from NVZ, but is not currently included in sea level rise predictions. Here, we use remotely sensed data to assess controls on NVZ glacier retreat between the 1973/6 and 2015. Glaciers that terminate into lakes or the ocean receded 3.5 times faster than those that terminate on land. Between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years, and we observe widespread slow-down in retreat, and even advance, between 2013 and 2015. There were some common patterns in the timing of glacier retreat, but the magnitude varied between individual glaciers. Rapid retreat between 2000–2013 corresponds to a period of significantly warmer air temperatures and reduced sea ice concentrations, and to changes in the NAO and AMO. We need to assess the impact of this accelerated retreat on dynamic ice losses from NVZ, to accurately quantify its future sea level rise contribution.

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Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30 000 years

Ocean Science ◽

10.5194/os-16-1017-2020 ◽

2020 ◽

Vol 16 (5) ◽

pp. 1017-1032

Author(s):

Heike H. Zimmermann ◽

Kathleen R. Stoof-Leichsenring ◽

Stefan Kruse ◽

Juliane Müller ◽

Ruediger Stein ◽

...

Keyword(s):

Sea Ice ◽

Ancient Dna ◽

Cold Water ◽

Taxonomic Composition ◽

Fram Strait ◽

Pcr Products ◽

Ideal Study ◽

Late Weichselian ◽

The Last Glacial Maximum ◽

The Last Glacial

Abstract. The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7 % of our sequences being assigned to diatoms across 18 different families, with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations – after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence.

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Cryosphere

Geography in America at the Dawn of the 21st Century ◽

10.1093/oso/9780198233923.003.0013 ◽

2004 ◽

Author(s):

Kenneth M. Hinkel ◽

Andrew W. Ellis

Keyword(s):

Sea Ice ◽

Snow Cover ◽

Global Climate ◽

Ice Sheets ◽

Past Century ◽

High Latitudes ◽

Ice Shelves ◽

The Past ◽

Third Assessment Report ◽

The Antarctic

The cryosphere refers to the Earth’s frozen realm. As such, it includes the 10 percent of the terrestrial surface covered by ice sheets and glaciers, an additional 14 percent characterized by permafrost and/or periglacial processes, and those regions affected by ephemeral and permanent snow cover and sea ice. Although glaciers and permafrost are confined to high latitudes or altitudes, areas seasonally affected by snow cover and sea ice occupy a large portion of Earth’s surface area and have strong spatiotemporal characteristics. Considerable scientific attention has focused on the cryosphere in the past decade. Results from 2 ×CO2 General Circulation Models (GCMs) consistently predict enhanced warming at high latitudes, especially over land (Fitzharris 1996). Since a large volume of ground and surface ice is currently within several degrees of its melting temperature, the cryospheric system is particularly vulnerable to the effects of regional warming. The Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) states that there is strong evidence of Arctic air temperature warming over land by as much as 5 °C during the past century (Anisimov et al. 2001). Further, sea-ice extent and thickness has recently decreased, permafrost has generally warmed, spring snow extent over Eurasia has been reduced, and there has been a general warming trend in the Antarctic (e.g. Serreze et al. 2000). Most climate models project a sustained warming and increase in precipitation in these regions over the twenty-first century. Projected impacts include melting of ice sheets and glaciers with consequent increase in sea level, possible collapse of the Antarctic ice shelves, substantial loss of Arctic Ocean sea ice, and thawing of permafrost terrain. Such rapid responses would likely have a substantial impact on marine and terrestrial biota, with attendant disruption of indigenous human communities and infrastructure. Further, such changes can trigger positive feedback effects that influence global climate. For example, melting of organic-rich permafrost and widespread decomposition of peatlands might enhance CO2 and CH4 efflux to the atmosphere. Cryospheric researchers are therefore involved in monitoring and documenting changes in an effort to separate the natural variability from that induced or enhanced by human activity.

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Decadal-scale sea ice changes in the Canadian Arctic and their impacts on humans during the past 4,000 years

Environmental Archaeology ◽

10.1179/env.2005.10.2.113 ◽

2005 ◽

Vol 10 (2) ◽

pp. 113-126 ◽

Cited By ~ 24

Author(s):

Peta J. Mudie ◽

Andre Rochon ◽

Elisabeth Levac

Keyword(s):

Sea Ice ◽

Canadian Arctic ◽

The Past ◽

Decadal Scale

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