SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Dalen Love) ;pers:(Stewart John R.)"

Sökning: WFRF:(Dalen Love) > Stewart John R.

  • Resultat 1-10 av 13
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Brace, Selina, et al. (författare)
  • Serial population extinctions in a small mammal indicate Late Pleistocene ecosystem instability
  • 2012
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:50, s. 20532-20536
  • Tidskriftsartikel (refereegranskat)abstract
    • The Late Pleistocene global extinction of many terrestrial mammal species has been a subject of intensive scientific study for over a century, yet the relative contributions of environmental changes and the global expansion of humans remain unresolved. A defining component of these extinctions is a bias toward large species, with the majority of small-mammal taxa apparently surviving into the present. Here, we investigate the population-level history of a key tundra-specialist small mammal, the collared lemming (Dicrostonyx torquatus), to explore whether events during the Late Pleistocene had a discernible effect beyond the large mammal fauna. Using ancient DNA techniques to sample across three sites in North-West Europe, we observe a dramatic reduction in genetic diversity in this species over the last 50,000 y. We further identify a series of extinction-recolonization events, indicating a previously unrecognized instability in Late Pleistocene small-mammal populations, which we link with climatic fluctuations. Our results reveal climate-associated, repeated regional extinctions in a keystone prey species across the Late Pleistocene, a pattern likely to have had an impact on the wider steppe-tundra community, and one that is concordant with environmental change as a major force in structuring Late Pleistocene biodiversity.
  •  
2.
  • Dalen, Love, et al. (författare)
  • Identifying Bird Remains Using Ancient DNA Barcoding
  • 2017
  • Ingår i: Genes. - : MDPI AG. - 2073-4425 .- 2073-4425. ; 8:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Bird remains that are difficult to identify taxonomically using morphological methods, are common in the palaeontological record. Other types of challenging avian material include artefacts and food items from endangered taxa, as well as remains from aircraft strikes. We here present a DNA-based method that enables taxonomic identification of bird remains, even from material where the DNA is heavily degraded. The method is based on the amplification and sequencing of two short variable parts of the 16S region in the mitochondrial genome. To demonstrate the applicability of this approach, we evaluated the method on a set of Holocene and Late Pleistocene postcranial bird bones from several palaeontological and archaeological sites in Europe with good success.
  •  
3.
  • Ersmark, Erik, et al. (författare)
  • Genetic turnovers and northern survival during the last glacial maximum in European brown bears
  • 2019
  • Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 9:10, s. 5891-5905
  • Tidskriftsartikel (refereegranskat)abstract
    • The current phylogeographic pattern of European brown bears (Ursus arctos) has commonly been explained by postglacial recolonization out of geographically distinct refugia in southern Europe, a pattern well in accordance with the expansion/contraction model. Studies of ancient DNA from brown bear remains have questioned this pattern, but have failed to explain the glacial distribution of mitochondrial brown bear clades and their subsequent expansion across the European continent. We here present 136 new mitochondrial sequences generated from 346 remains from Europe, ranging in age between the Late Pleistocene and historical times. The genetic data show a high Late Pleistocene diversity across the continent and challenge the strict confinement of bears to traditional southern refugia during the last glacial maximum (LGM). The mitochondrial data further suggest a genetic turnover just before this time, as well as a steep demographic decline starting in the mid-Holocene. Levels of stable nitrogen isotopes from the remains confirm a previously proposed shift toward increasing herbivory around the LGM in Europe. Overall, these results suggest that in addition to climate, anthropogenic impact and inter-specific competition may have had more important effects on the brown bear's ecology, demography, and genetic structure than previously thought.
  •  
4.
  • Lagerholm, Vendela K., et al. (författare)
  • Range shifts or extinction? Ancient DNA and distribution modelling reveal past and future responses to climate warming in cold-adapted birds
  • 2017
  • Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 23:4, s. 1425-1435
  • Tidskriftsartikel (refereegranskat)abstract
    • Global warming is predicted to cause substantial habitat rearrangements, with the most severe effects expected to occur in high-latitude biomes. However, one major uncertainty is whether species will be able to shift their ranges to keep pace with climate-driven environmental changes. Many recent studies on mammals have shown that past range contractions have been associated with local extinctions rather than survival by habitat tracking. Here, we have used an interdisciplinary approach that combines ancient DNA techniques, coalescent simulations and species distribution modelling, to investigate how two common cold-adapted bird species, willow and rock ptarmigan (Lagopus lagopus and Lagopus muta), respond to long-term climate warming. Contrary to previous findings in mammals, we demonstrate a genetic continuity in Europe over the last 20 millennia. Results from back-casted species distribution models suggest that this continuity may have been facilitated by uninterrupted habitat availability and potentially also the greater dispersal ability of birds. However, our predictions show that in the near future, some isolated regions will have little suitable habitat left, implying a future decrease in local populations at a scale unprecedented since the last glacial maximum.
  •  
5.
  •  
6.
  • Lord, Edana, et al. (författare)
  • Population dynamics and demographic history of Eurasian collared lemmings
  • 2022
  • Ingår i: BMC Ecology and Evolution. - : Springer Science and Business Media LLC. - 2730-7182. ; 22:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Ancient DNA studies suggest that Late Pleistocene climatic changes had a significant effect on population dynamics in Arctic species. The Eurasian collared lemming (Dicrostonyx torquatus) is a keystone species in the Arctic ecosystem. Earlier studies have indicated that past climatic fluctuations were important drivers of past population dynamics in this species.Results: Here, we analysed 59 ancient and 54 modern mitogenomes from across Eurasia, along with one modern nuclear genome. Our results suggest population growth and genetic diversification during the early Late Pleistocene, implying that collared lemmings may have experienced a genetic bottleneck during the warm Eemian interglacial. Furthermore, we find multiple temporally structured mitogenome clades during the Late Pleistocene, consistent with earlier results suggesting a dynamic late glacial population history. Finally, we identify a population in northeastern Siberia that maintained genetic diversity and a constant population size at the end of the Pleistocene, suggesting suitable conditions for collared lemmings in this region during the increasing temperatures associated with the onset of the Holocene.Conclusions: This study highlights an influence of past warming, in particular the Eemian interglacial, on the evolutionary history of the collared lemming, along with spatiotemporal population structuring throughout the Late Pleistocene.
  •  
7.
  • Palkopoulou, Eleftheria, et al. (författare)
  • Synchronous genetic turnovers across Western Eurasia in Late Pleistocene collared lemmings
  • 2016
  • Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 22:5, s. 1710-1721
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D.torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next-generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D.torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50000years. The observation of repeated extinctions across such a vast geographical range indicates large-scale changes in the steppe-tundra environment in western Eurasia during the last glaciation. AllHolocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D.torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D.groenlandicus and D.richardsoni were recovered from a Late Pleistocene site in south-western Canada. This suggests that D.groenlandicus had a more southern and D.richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex demographical history, which could have had bottom-up effects in the Late Pleistocene steppe-tundra ecosystem.
  •  
8.
  • Rabiniak, Emilia, et al. (författare)
  • Late Pleistocene and Holocene pikas (Mammalia, Lagomorpha) from Europe and the validity of Ochotona spelaea : New insights based on mtDNA analysis
  • 2023
  • Ingår i: Palaeontologia Electronica. - : Coquina Press. - 1935-3952 .- 1094-8074. ; 26:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Pikas were among small mammals that inhabited mammoth steppes during the last glacial. The evolutionary history of ochotonids in Europe is relatively well studied, although the taxonomic status of many described forms remains ambiguous, and the majority of extant species of the genus Ochotona are poorly represented in the fossil record. The present study aims to analyse the taxonomic relationships of a sample of Late Pleistocene-Holocene pikas based on mtDNA data and to clarify the status of the species described from Europe. A phylogenetic analysis has revealed that pikas form two large clades: one includes O. pusilla and the other includes the extant Asian and North American species. The study of haplotypes has shown similar results. The analysis supports the view that in the Late Pleistocene and Holocene O. pusilla was distributed throughout Europe, and its geographic range has contracted to the east until reaching its modern limits. The analysis of samples provided evidence that O. pusilla had survived in Eastern Europe until relatively recently and disappeared only about 150 years ago. The molecular data inferred from mtDNA do not support the species status of O. spelaea, despite morphological differences possibly related to the particular ecology of the Late Pleistocene.
  •  
9.
  •  
10.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 13

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy