Oliver Kersten

• Kersten, Oliver Sven; Star, Bastiaan; Krabberød, Anders Kristian; Atmore, Lane; Tørresen, Ole K. & Anker-Nilssen, Tycho [Vis alle 12 forfattere av denne artikkelen] (2023). Hybridization of Atlantic puffins in the Arctic coincides with 20th-century climate change. Science Advances. ISSN 2375-2548. 9(40). doi: 10.1126/sciadv.adh1407. Fulltekst i vitenarkiv Vis sammendrag

  The Arctic is experiencing the fastest rates of global warming,leading to shifts in the distribution of its biota and increasing the potential for hybridization. However, genomic evidenc eof recent hybridization events in the Arctic remains unexpectedly rare. Here, we use whole-genome sequencing of contemporary and 122-year-old historical specimens to investigate the origin of an Arctic hybrid population of Atlantic puffins(Fratercula arctica) on Bjørnøya, Norway. We show that the hybridization between the High Arctic, large-bodied subspecies F.a. naumanni and the temperate, smaller-sized subspecies F.a. arctica began as recently as six generations ago due to an unexpected southward range expansion of F.a. naumanni. Moreover, we find a significant temporal loss of genetic diversity across Arctic and temperate puffin populations.Our observations provide compelling genomic evidence of the impacts of recent distributional shifts and loss of diversity in Arctic communities during the 20th century.

• Leigh, Deborah M.; Kersten, Oliver Sven; Star, Bastiaan; Anker-Nilssen, Tycho; Burnham, Kurt & Johnson, Jeff [Vis alle 8 forfattere av denne artikkelen] (2022). Sympatry of genetically distinct Atlantic Puffins (Fratercula arctica) in the High Arctic. IBIS. ISSN 0019-1019. 165(3), s. 1022–1030. doi: 10.1111/ibi.13153. Fulltekst i vitenarkiv
• Guellil, Meriam; Rinaldo, Natascia; Zedda, Nicoletta; Kersten, Oliver; Gonzalez Muro, Xabier & Stenseth, Nils Chr. [Vis alle 8 forfattere av denne artikkelen] (2021). Bioarchaeological insights into the last plague of Imola (1630–1632). Scientific Reports. ISSN 2045-2322. 11(1), s. 1–12. doi: 10.1038/s41598-021-98214-2. Fulltekst i vitenarkiv
• Kersten, Oliver; Star, Bastiaan; Leigh, Deborah M.; Anker-Nilssen, Tycho; Strøm, Hallvard & Danielsen, Jóhannis [Vis alle 17 forfattere av denne artikkelen] (2021). Complex population structure of the Atlantic puffin revealed by whole genome analyses. Communications Biology. ISSN 2399-3642. 4. doi: 10.1038/s42003-021-02415-4. Fulltekst i vitenarkiv Vis sammendrag

  The factors underlying gene flow and genomic population structure in vagile seabirds are notoriously difficult to understand due to their complex ecology with diverse dispersal barriers and extensive periods at sea. Yet, such understanding is vital for conservation management of seabirds that are globally declining at alarming rates. Here, we elucidate the population structure of the Atlantic puffin (Fratercula arctica) by assembling its reference genome and analyzing genome-wide resequencing data of 72 individuals from 12 colonies. We identify four large, genetically distinct clusters, observe isolation-by-distance between colonies within these clusters, and obtain evidence for a secondary contact zone. These observations disagree with the current taxonomy, and show that a complex set of contemporary biotic factors impede gene flow over different spatial scales. Our results highlight the power of whole genome data to reveal unexpected population structure in vagile marine seabirds and its value for seabird taxonomy, evolution and conservation.

• Ferrari, Giada; Cuevas, Angelica; Wyrozemska, Agata Teresa; Ballantyne, Rachel; Kersten, Oliver & Palsdottir, Albina Hulda [Vis alle 18 forfattere av denne artikkelen] (2021). The preservation of ancient DNA in archaeological fish bone. Journal of Archaeological Science. ISSN 0305-4403. 126. doi: 10.1016/j.jas.2020.105317. Fulltekst i vitenarkiv
• Guellil, Meriam; Kersten, Oliver; Namouchi, Amine; Luciani, Stefania; Marota, Isolina & Arcini, Caroline [Vis alle 17 forfattere av denne artikkelen] (2020). A genomic and historical synthesis of plague in 18th century Eurasia. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 117(45), s. 28328–28335. doi: 10.1073/pnas.2009677117. Fulltekst i vitenarkiv
• Laroche, Olivier; Kersten, Oliver; Smith, Craig R. & Goetze, Erica (2020). Environmental DNA surveys detect distinct metazoan communities across abyssal plains and seamounts in the western Clarion Clipperton Zone. Molecular Ecology. ISSN 0962-1083. 29(23), s. 4588–4604. doi: 10.1111/mec.15484. Fulltekst i vitenarkiv
• Laroche, Oliver; Kersten, Oliver; Smith, Craig R. & Goetze, Erica (2020). From sea surface to seafloor: A benthic allochthonous eDNA survey for the abyssal ocean. Frontiers in Marine Science. ISSN 2296-7745. 7, s. 1–16. doi: 10.3389/fmars.2020.00682. Fulltekst i vitenarkiv
• Ottoni, Claudio; Guellil, Meriam; Ozga, Andrew; Stone, Anne; Kersten, Oliver & Bramanti, Barbara [Vis alle 8 forfattere av denne artikkelen] (2019). Metagenomic analysis of dental calculus in ancient Egyptian baboons. Scientific Reports. ISSN 2045-2322. 9, s. 1–10. doi: 10.1038/s41598-019-56074-x. Fulltekst i vitenarkiv Vis sammendrag

  Dental calculus, or mineralized plaque, represents a record of ancient biomolecules and food residues. Recently, ancient metagenomics made it possible to unlock the wealth of microbial and dietary information of dental calculus to reconstruct oral microbiomes and lifestyle of humans from the past. Although most studies have so far focused on ancient humans, dental calculus is known to form in a wide range of animals, potentially informing on how human-animal interactions changed the animals’ oral ecology. Here, we characterise the oral microbiome of six ancient Egyptian baboons held in captivity during the late Pharaonic era (9th–6th centuries BC) and of two historical baboons from a zoo via shotgun metagenomics. We demonstrate that these captive baboons possessed a distinctive oral microbiome when compared to ancient and modern humans, Neanderthals and a wild chimpanzee. These results may reflect the omnivorous dietary behaviour of baboons, even though health, food provisioning and other factors associated with human management, may have changed the baboons’ oral microbiome. We anticipate our study to be a starting point for more extensive studies on ancient animal oral microbiomes to examine the extent to which domestication and human management in the past affected the diet, health and lifestyle of target animals.

• Kersten, Oliver; Vetter, Eric W.; Jungbluth, Michelle J.; Smith, Craig R. & Goetze, Erica (2019). Larval assemblages over the abyssal plain in the Pacific are highly diverse and spatially patchy. PeerJ. ISSN 2167-8359. 7, s. 1–36. doi: 10.7717/peerj.7691. Fulltekst i vitenarkiv Vis sammendrag

  Abyssal plains are among the most biodiverse yet least explored marine ecosystems on our planet, and they are increasingly threatened by human impacts, including future deep seafloor mining. Recovery of abyssal populations from the impacts of polymetallic nodule mining will be partially determined by the availability and dispersal of pelagic larvae leading to benthic recolonization of disturbed areas of the seafloor. Here we use a tree-of-life (TOL) metabarcoding approach to investigate the species richness, diversity, and spatial variability of the larval assemblage at mesoscales across the abyssal seafloor in two mining-claim areas in the eastern Clarion Clipperton Fracture Zone (CCZ; abyssal Pacific). Our approach revealed a previously unknown taxonomic richness within the meroplankton assemblage, detecting larvae from 12 phyla, 23 Classes, 46 Orders, and 65 Families, including a number of taxa not previously reported at abyssal depths or within the Pacific Ocean. A novel suite of parasitic copepods and worms were sampled, from families that are known to associate with other benthic invertebrates or demersal fishes as hosts. Larval assemblages were patchily distributed at the mesoscale, with little similarity in OTUs detected among deployments even within the same 30 × 30 km study area. Our results provide baseline observations on larval diversity prior to polymetallic nodule mining in this region, and emphasize our overwhelming lack of knowledge regarding larvae of the benthic boundary layer in abyssal plain ecosystems.

• Namouchi, Amine; Guellil, Meriam; Kersten, Oliver; Hänsch, Stephanie; Ottoni, Claudio & Schmid, Boris Valentijn [Vis alle 16 forfattere av denne artikkelen] (2018). Integrative approach using Yersinia pestis genomes to revisit the historical landscape of plague during the Medieval Period. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 115(50), s. E11790–E11797. doi: 10.1073/pnas.1812865115. Fulltekst i vitenarkiv Vis sammendrag

  Over the last few years, genomic studies on Yersinia pestis, the causative agent of all known plague epidemics, have considerably increased in numbers, spanning a period of about 5,000 y. Nonetheless, questions concerning historical reservoirs and routes of transmission remain open. Here, we present and describe five genomes from the second half of the 14th century and reconstruct the evolutionary history of Y. pestis by reanalyzing previously published genomes and by building a comprehensive phylogeny focused on strains attributed to the Second Plague Pandemic (14th to 18th century). Corroborated by historical and ecological evidence, the presented phylogeny, which includes our Y. pestis genomes, could support the hypothesis of an entry of plague into Western European ports through distinct waves of introduction during the Medieval Period, possibly by means of fur trade routes, as well as the recirculation of plague within the human population via trade routes and human movement.

• Guellil, Meriam; Kersten, Oliver; Namouchi, Amine; Bauer, Egil Lindhart; Derrick, Michael & Jensen, Anne Østergaard [Vis alle 8 forfattere av denne artikkelen] (2018). Genomic blueprint of a relapsing fever pathogen in 15th century Scandinavia. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 115(41), s. 10422–10427. doi: 10.1073/pnas.1807266115. Fulltekst i vitenarkiv Vis sammendrag

  Louse-borne relapsing fever (LBRF) is known to have killed millions of people over the course of European history and remains a major cause of mortality in parts of the world. Its pathogen, Borrelia recurrentis, shares a common vector with global killers such as typhus and plague and is known for its involvement in devastating historical epidemics such as the Irish potato famine. Here, we describe a European and historical genome of B. recurrentis, recovered from a 15th century skeleton from Oslo. Our distinct European lineage has a discrete genomic makeup, displaying an ancestral oppA-1 gene and gene loss in antigenic variation sites. Our results illustrate the potential of ancient DNA research to elucidate dynamics of reductive evolution in a specialized human pathogen and to uncover aspects of human health usually invisible to the archaeological record.

• Kersten, Oliver; Smith, Craig R. & Vetter, Eric W. (2017). Abyssal near-bottom dispersal stages of benthic invertebrates in the Clarion-Clipperton polymetallic nodule province. Deep Sea Research Part I: Oceanographic Research Papers. ISSN 0967-0637. 127, s. 31–40. doi: 10.1016/j.dsr.2017.07.001. Vis sammendrag

  Growing interest in polymetallic nodule mining has intensified the need to characterize the abundance, community structure and vertical flux of meroplankton in the Clarion-Clipperton Zone (CCZ) to facilitate the estimation of larval supply and potential connectivity of benthic populations. These ecological parameters are essential to predict recolonization processes following the expected large-scale, high intensity disturbances associated with nodule extraction. Here, we present the first description of the composition, abundance, temporal variability, and mesoscale distribution of dispersing stages of the benthos in two study areas in the eastern CCZ. Samples from free-vehicle plankton pumps showed little variation in meroplankton diversity and abundance over scales of 30–100 km for time scales of days to weeks. However, sediment-trap samples revealed high temporal variability in vertical flux over weeks to months. Larval abundances and fluxes measured in the abyssal CCZ are ~ 1–2 orders of magnitude lower than observed at deep-sea ridge and hydrothermal-vent habitats. We found significantly higher downward larval fluxes at 11 m above the bottom (mab) than at 146 mab, indicating accumulation or retention of meroplankton within the Benthic Boundary Layer (BBL). The high abundance of meroplankton in the BBL emphasizes its importance to dispersing stages and suggests that the creation of large sediment plumes in the BBL during nodule mining could compromise the dispersal and recruitment abilities of the abyssal benthos, potentially slowing rates and altering patterns of benthic community recovery following mining disturbance.

• Ajani, Penelope A.; Armbrecht, Linda H.; Kersten, Oliver; Kohli, Gurjeet S. & Murray, Shauna A. (2016). Diversity, temporal distribution and physiology of the centric diatom Leptocylindrus Cleve (Bacillariophyta) from a southern hemisphere upwelling system. Diatom Research. ISSN 0269-249X. 31(4), s. 351–365. doi: 10.1080/0269249X.2016.1260058.

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• Kersten, Oliver Sven (2023). Sea Parrot Genomics: Linking Past and Present Population Structure of the Atlantic Puffin (Fratercula arctica).
• Kersten, Oliver Sven (2021). Complex population structure of the Atlantic puffin revealed by whole genome analyses.
• Palsdottir, Albina Hulda; Kersten, Oliver Sven; Star, Bastiaan; Nistelberger, Heidi Maria; Kantanen, Juha & Hallsson, Jón Hallsteinn [Vis alle 7 forfattere av denne artikkelen] (2021). The tangled history of sheep in the North Atlantic revealed through ancient DNA. Vis sammendrag

  Sheep played a vital role in the settlement of the North Atlantic in the Viking Age, providing wool for clothing and the sails of Viking ships in addition to milk, meat, skins and horns. Despite their importance we know little about how the rapid settlement of the North Atlantic shaped the population structure and genetic diversity of sheep and how the local breeds in the North Atlantic region have changed through a thousand years of isolation. We sequenced over 80 ancient sheep bones from archaeological excavations in the North Atlantic resulting in 28 ancient sheep genomes (800-1700 CE) with average coverage of 3,7X and eight genomes from modern landrace breeds present in the region. The population history of sheep in the North Atlantic is more complicated than previously thought with some evidence of admixture of sheep from Norway and the UK during the founding of the Icelandic sheep population. The sheep population in Norse Greenland is clearly founded from Iceland. In Greenland we observe a loss of heterozygosity and increases in inbreeding over time, probably related to population decline associated with the collapse of the Norse settlement in Greenland. Our data shows a large reduction in genomic diversity of sheep in the North Atlantic from the Viking and Medieval period to the modern sheep breeds in the region, specifically in Iceland and the Faroe Islands.

• Palsdottir, Albina Hulda; Kersten, Oliver; Star, Bastiaan; Nistelberger, Heidi Maria; Kantanen, Juha & Hallsson, Jón Hallsteinn [Vis alle 7 forfattere av denne artikkelen] (2021). Genetic history of sheep in the North Atlantic from the Viking Age to modern breeds. Vis sammendrag

  Sheep were vital to subsistence in the newly settled lands of the Norse in the Faroes, Iceland and Greenland during the Viking Age. Sheep are multi-product animals and were reared for wool, milk, meat, skins and horns, and large number of sheep bones have been found in archaeological excavations in the region. Despite their importance, the origins of local sheep breeds and their development since the 9th century are poorly understood. Here we obtained whole genome sequences of 27 ancient sheep from archaeological excavations in Iceland, Greenland, the Faroe Islands, Norway and the UK dating from 800-1700. For comparison we also analysed both newly generated and previously published modern genomes from North Atlantic, European and Asian sheep breeds. We trace the introduction of sheep to the Faroes, Iceland and Greenland in a clear stepping stone pattern, but ancient UK and Norwegian sheep form an overlapping cluster. Moreover, our data shows a large reduction in genomic diversity of sheep in the North Atlantic from the Viking and Medieval period to the modern sheep breeds in the region.

• Namouchi, Amine; Guellil, Meriam; Kersten, Oliver Sven; Hänsch, Stephanie; Ottoni, Claudio & Schmid, Boris Valentijn [Vis alle 16 forfattere av denne artikkelen] (2020). Correction for Namouchi et al., Integrative approach using Yersinia pestis genomes to revisit the historical landscape of plague during the Medieval Period. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 17(22). doi: 10.1073/pnas.2007983117.
• Kersten, Oliver; Star, Bastiaan; Anker-Nilssen, Tycho; Strøm, Hallvard & Boessenkool, Sanne (2019). Genomic population structure of the Atlantic Puffin – insights into the species’ taxonomy.
• Kersten, Oliver (2016). Yersinia pestis genomes from medieval Europe and Asia during the 2nd plague pandemic.
• Kersten, Oliver Sven (2023). Sea Parrot Genomics: Linking past and present population structure and demography of the Atlantic puffin (Fratercula arctica). University of Oslo. ISSN 1501-7710.

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