Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Consequences of a demographic bottleneck on geneticstructure and variation in the Scandinavian brown bear
Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of National History, Sweden.
Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of National History, Sweden.
Show others and affiliations
Number of Authors: 7
2015 (English)In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 24, no 13, 3441-3454 p.Article in journal (Refereed) Published
Abstract [en]

The Scandinavian brown bear went through a major decline in population size approximately 100years ago, due to intense hunting. After being protected, the population subsequently recovered and today numbers in the thousands. The genetic diversity in the contemporary population has been investigated in considerable detail, and it has been shown that the population consists of several subpopulations that display relatively high levels of genetic variation. However, previous studies have been unable to resolve the degree to which the demographic bottleneck impacted the contemporary genetic structure and diversity. In this study, we used mitochondrial and microsatellite DNA markers from pre- and postbottleneck Scandinavian brown bear samples to investigate the effect of the bottleneck. Simulation and multivariate analysis suggested the same genetic structure for the historical and modern samples, which are clustered into three subpopulations in southern, central and northern Scandinavia. However, the southern subpopulation appears to have gone through a marked change in allele frequencies. When comparing the mitochondrial DNA diversity in the whole population, we found a major decline in haplotype numbers across the bottleneck. However, the loss of autosomal genetic diversity was less pronounced, although a significant decline in allelic richness was observed in the southern subpopulation. Approximate Bayesian computations provided clear support for a decline in effective population size during the bottleneck, in both the southern and northern subpopulations. These results have implications for the future management of the Scandinavian brown bear because they indicate a recent loss in genetic diversity and also that the current genetic structure may have been caused by historical ecological processes rather than recent anthropogenic persecution.

Place, publisher, year, edition, pages
2015. Vol. 24, no 13, 3441-3454 p.
Keyword [en]
bottleneck, decline, microsatellites, mtDNA, Ursus arctos
National Category
Evolutionary Biology
Research subject
Systematic Zoology
Identifiers
URN: urn:nbn:se:su:diva-119131DOI: 10.1111/mec.13239ISI: 000356973100018OAI: oai:DiVA.org:su-119131DiVA: diva2:843782
Available from: 2015-07-31 Created: 2015-07-29 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Large carnivore population turnover and ecological change during the Late Quaternary
Open this publication in new window or tab >>Large carnivore population turnover and ecological change during the Late Quaternary
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The cave lion (Panthera spelaea), the grey wolf (Canis lupus) and the brown bear (Ursus arctos) all shared an intercontinental distribution across the northern hemisphere during most of the Late Quaternary, and experienced repeated events of climate change. The cave lion went extinct at the end of the Pleistocene and although the wolf and the bear have survived until present day, recent human persecution has caused demographic bottlenecks and local extinctions. In this thesis, mitochondrial and nuclear DNA was analyzed from ancient and modern samples in order to study spatiotemporal changes in genetic diversity in the three species. Mitochondrial sequences analyzed from 48 radiocarbon dated cave lion remains revealed two haplogroups, of which the more genetically diverse seemingly disappeared around 41,000 years BP. Serial coalescent simulations on the data supported a population bottleneck in Beringia between roughly 47-18,000 years BP. Its long duration prevents a specific causal factor to be singled out, but the early onset and overlapping declines of other large mammals in the region suggests that major environmental changes greatly impacted the fauna of Beringia during this time. Using a similar genetic marker, a set of 126 modern wolves and two Siberian wolf remains of Late Pleistocene age were analyzed. The sequences yielded from the latter samples pertained to a basal haplogroup, which contained all Late Pleistocene wolves from previous studies. As data from both modern and ancient wolves were combined, a pattern of decreasing genetic diversity was identified around the Pleistocene-Holocene transition. This decrease was further tested by serial coalescent simulations, which supported a bottleneck in northern North America around this time. Further analyses were applied to one of the ancient wolf remains from Siberia, producing a draft genome sequence and a complete mitochondrial genome. Given the radiocarbon date of the Siberian wolf, a slower mutation rate could be inferred, which pushed back the split between the lineages leading to modern wolves and dogs to at least 27,000 years BP. The Siberian wolf was positioned close to the split but basal to these lineages. A global comparison with modern dogs indicated a closer genetic affiliation between the Siberian wolf and some arctic breeds. For the brown bear, phylogeographic changes in Europe were studied over the last 50,000 years, using radiocarbon dating and mitochondrial sequences. When concatenated and compared with published data, the mtDNA revealed a turnover event just before the LGM, while the dating confirmed a presence of brown bears at relatively high latitudes during this period. Marked shifts in population size were also inferred. Furthermore, data of stable isotope levels confirmed a dietary shift to increasing herbivory around the LGM. Finally, a recent anthropogenic bottleneck among Scandinavian brown bears was studied. While no change in genetic structure could be detected, mitochondrial and microsatellite markers showed a decline in genetic diversity, especially pronounced in the southern subpopulation. ABC simulations supported a bottleneck taking place across all of Scandinavia. Taken together, this thesis have identified and elucidated several impacts on genetic diversity in the past populations of large carnivores. The use of different genetic markers has enabled comparisons with published data, but also revealed their comparatively different benefits and limitations. Overall, the presented studies compose a synthesis of past population dynamics in large carnivores, uniquely revealed by ancient DNA.

Place, publisher, year, edition, pages
Stockholm: Department of Zoology, Stockholm University, 2016
National Category
Evolutionary Biology
Research subject
Systematic Zoology
Identifiers
urn:nbn:se:su:diva-127845 (URN)978-91-7649-380-9 (ISBN)
Public defence
2016-04-29, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript.

Available from: 2016-04-06 Created: 2016-03-13 Last updated: 2017-02-17Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Ersmark, ErikDalén, Love
By organisation
Department of Zoology
In the same journal
Molecular Ecology
Evolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 114 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf