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  • 1.
    Dalerum, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Oviedo, Spain; University of Pretoria, South Africa.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Fröjd, Christina
    Lecomte, Nicolas
    Lindgren, Åsa
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology.
    Pečnerová, Patrícia
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Spatial variation in Arctic hare (Lepus arcticus) populations around the Hall Basin2017In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 40, no 10, p. 2113-2118Article in journal (Refereed)
    Abstract [en]

    Arctic environments have relatively simple ecosystems. Yet, we still lack knowledge of the spatio-temporal dynamics of many Arctic organisms and how they are affected by local and regional processes. The Arctic hare (Lepus arcticus) is a large lagomorph endemic to high Arctic environments in Canada and Greenland. Current knowledge about this herbivore is scarce and the temporal and spatial dynamics of their populations are poorly understood. Here, we present observations on Arctic hares in two sites on north Greenland (Hall and Washington lands) and one adjacent site on Ellesmere Island (Judge Daly Promontory). We recorded a large range of group sizes from 1 to 135 individuals, as well as a substantial variation in hare densities among the three sites (Hall land: 0 animals/100 km(2), Washington land 14.5-186.7 animals/100 km(2), Judge Daly Promontory 0.18-2.95 animals/100 km(2)). However, pellet counts suggested that both Hall land and Judge Daly Promontory hosted larger populations at other times. We suggest that our results could have been caused by three spatially differentiated populations with asynchronous population fluctuations. With food limitation being a likely driver behind the observed variation, we argue that food limitation likely interacts with predation and competition in shaping the spatial dynamics of Arctic hares in this region.

  • 2.
    Dalerum, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Oviedo, Spain; University of Pretoria, South Africa.
    Freire, S.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Lecomte, N.
    Lindgren, A.
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology.
    Pečnerová, Patricia
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Exploring the diet of arctic wolves (Canis lupus arctos) at their northern range limit2018In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 96, no 3, p. 277-281Article in journal (Refereed)
    Abstract [en]

    The grey wolf (Canis lupus Linnaeus, 1758) is one of the most widespread large carnivores on Earth, and occurs throughout the Arctic. Although wolf diet is well studied, we have scant information from high Arctic areas. Global warming is expected to increase the importance of predation for ecosystem regulation in Arctic environments. To improve our ability to manage Arctic ecosystems under environmental change, we therefore need knowledge about Arctic predator diets. Prey remains in 54 wolf scats collected at three sites in the high Arctic region surrounding the Hall Basin (Judge Daly Promontory, Ellesmere Island, Canada, and Washington Land and Hall Land, both in northwestern Greenland) pointed to a dietary importance of arctic hare (Lepus arcticus Ross, 1819; 55% frequency of occurrence) and muskoxen (Ovibos moschatus (Zimmermann, 1780); 39% frequency of occurrence), although we observed diet variation among the sites. A literature compilation suggested that arctic wolves (Canis lupus arctos Pocock, 1935) preferentially feed on caribou (Rangifer tarandus (Linnaeus, 1758)) and muskoxen, but can sustain themselves on arctic hares and Greenland collared lemmings (Dicrostonyx groenlandicus (Traill, 1823)) in areas with limited or no ungulate populations. We suggest that climate change may alter the dynamics among wolves, arctic hare, muskoxen, and caribou, and we encourage further studies evaluating how climate change influences predator-prey interactions in high Arctic environments.

  • 3.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    DNA analysis on fox faeces and competition induced niche shifts2004In: Molecular Ecology, ISSN 0962-1083, Vol. 13, no 8, p. 2389-2392Article in journal (Refereed)
    Abstract [en]

    Interference competition can force inferior competitors to change their distribution patterns. It is, however, possible that the dominant competitor poses a higher threat during certain times of the year, for example during reproduction. In such cases, the inferior competitor is expected to change its distribution accordingly. We used a molecular species identification method on faeces to investigate how the spatial overlap between arctic and red foxes changes between seasons. The results show that arctic and red foxes are sympatric during winter, but allopatric in summer as arctic foxes retreat to higher altitudes further from the tree-line during the breeding season

  • 4.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Fuglei, Eva
    Hersteinsson, Pall
    Kapel, Christion M.O.
    Roth, James D.
    Samelius, Gustaf
    Tannerfeldt, Magnus
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Population history and genetic structure of a circumpolar species: the arctic fox2005In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 84, no 1, p. 79-89Article in journal (Refereed)
    Abstract [en]

    The circumpolar arctic fox Alopex lagopus thrives in cold climates and has a high migration rate involving long-distance movements. Thus, it differs from many temperate taxa that were subjected to cyclical restriction in glacial refugia during the Ice Ages. We investigated population history and genetic structure through mitochondrial control region variation in 191 arctic foxes from throughout the arctic. Several haplotypes had a Holarctic distribution and no phylogeographical structure was found. Furthermore, there was no difference in haplotype diversity between populations inhabiting previously glaciated and unglaciated regions. This suggests current gene flow among the studied populations, with the exception of those in Iceland, which is surrounded by year-round open water. Arctic foxes have often been separated into two ecotypes: ‘lemming’ and ‘coastal’. An analysis of molecular variance suggested particularly high gene flow among populations of the ‘lemming’ ecotype. This could be explained by their higher migration rate and reduced fitness in migrants between ecotypes. A mismatch analysis indicated a sudden expansion in population size around 118 000 BP, which coincides with the last interglacial. We propose that glacial cycles affected the arctic fox in a way opposite to their effect on temperate species, with interglacials leading to short-term isolation in northern refugia.

  • 5.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Götherström, Anders
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Archaeological Research Laboratory.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Identifying species from pieces of faeces2004In: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 5, no 1, p. 109-111Article in journal (Refereed)
  • 6.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Götherström, Anders
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Archaeological Research Laboratory.
    Tannerfeldt, Magnus
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Is the endangered Fennoscandian arctic fox (Alopex lagopus) population genetically isolated?2002In: Biological Conservation, Vol. 105, no 2, p. 171-178Article in journal (Refereed)
    Abstract [en]

    The arctic fox population in Fennoscandia is on the verge of going extinct after not being able to recover from a severe bottleneck at the end of the 19th century. The Siberian arctic fox population, on the other hand, is large and unthreatened. In order to resolve questions regarding gene flow between, and genetic variation within the populations, a 294 bp long part of the mitochondrial hypervariable region 1 was sequenced. This was done for 17 Swedish, 15 Siberian and two farmed foxes. Twelve variable nucleotide sites were observed, which resulted in 10 different haplotypes. Three haplotypes were found in Sweden and seven haplotypes were found in Siberia. An analysis of molecular variance showed a weak, but significant, differentiation between the populations. No difference in haplotype diversity was found between the populations. A phylogenetic analysis revealed that the three Swedish haplotypes were not monophyletic compared to the Siberian haplotypes. These results indicate a certain amount of gene flow between the two populations. both before and after the bottleneck. Restocking the Fennoscandian population with arctic foxes from Siberia might therefore be a viable option.

  • 7.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kvaloy, K.
    Linnell, J. D. C.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology.
    Strand, O.
    Tannerfeldt, M.
    Henttonen, H.
    Fuglei, E.
    Landa, A.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Population structure in a critically endangered arctic fox population: does genetics matter?2006In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 15, no 10, p. 2809-2819Article in journal (Refereed)
    Abstract [en]

    The arctic fox (Alopex lagopus) in Scandinavia is classified as critically endangered after having gone through a severe decline in population size in the beginning of the 20th century, from which it has failed to recover despite more than 65 years of protection. Arctic foxes have a high dispersal rate and often disperse over long distances, suggesting that there was probably little population differentiation within Scandinavia prior to the bottleneck. It is, however, possible that the recent decline in population size has led to a decrease in dispersal and an increase in population fragmentation. To examine this, we used 10 microsatellite loci to analyse genetic variation in 150 arctic foxes from Scandinavia and Russia. The results showed that the arctic fox in Scandinavia presently is subdivided into four populations, and that the Kola Peninsula and northwest Russia together form a large fifth population. Current dispersal between the populations seemed to be very low, but genetic variation within them was relatively high. This and the relative F-ST values among the populations are consistent with a model of recent fragmentation within Scandinavia. Since the amount of genetic variation is high within the populations, but the populations are small and isolated, demographic stochasticity seems to pose a higher threat to the populations' persistence than inbreeding depression and low genetic variation.

  • 8.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nyström, Veronica
    Stockholm University, Faculty of Science, Department of Zoology.
    Valdiosera, Cristina
    Germonpre, Mietje
    Sablin, Mikhail
    Turner, Elaine
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Arsuaga, Juan Luis
    Götherström, Anders
    Ancient DNA reveals lack of postglacial habitat tracking in the arctic fox2007In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 104, no 16, p. 6726-6729Article in journal (Refereed)
    Abstract [en]

    How species respond to an increased availability of habitat, for example at the end of the last glaciation, has been well established. In contrast, little is known about the opposite process, when the amount of habitat decreases. The hypothesis of habitat tracking predicts that species should be able to track both increases and decreases in habitat availability. The alternative hypothesis is that populations outside refugia become extinct during periods of unsuitable climate. To test these hypotheses, we used ancient DNA techniques to examine genetic variation in the arctic fox (Alopex lagopus) through an expansion/contraction cycle. The results show that the arctic fox in midlatitude Europe became extinct at the end of the Pleistocene and did not track the habitat when it shifted to the north. Instead, a high genetic similarity between the extant populations in Scandinavia and Siberia suggests an eastern origin for the Scandinavian population at the end of the last glaciation. These results provide new insights into how species respond to climate change, since they suggest that populations are unable to track decreases in habitat avaliability. This implies that arctic species may be particularly vulnerable to increases in global temperatures.

  • 9.
    Dalén, Lové
    et al.
    Ctr Mixto UCM, ISCIII Evolut & Comportamiento Humanos, Madrid 28029, Spain .
    Götherström, Anders
    Uppsala Univ, Evolutionary Biol Ctr, S-75236 Uppsala, Sweden .
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Shapiro, B
    Univ Oxford, Dept Zool, Oxford OX1 3PS, England.
    Recovery of DNA from Footprints in the snow2008In: Canadian field-naturalist, ISSN 0008-3550, Vol. 121, no 3, p. 321-324Article in journal (Refereed)
    Abstract [en]

    The recovery of trace amounts of DNA has been demonstrated to be a reliable tool in conservation genetics and has become a key component of modern forensic casework. To date, genetic data have been successfully recovered from a variety of sources, including biological fluids, faeces, clothing, and even directly from fingerprints. However, to our knowledge and despite their widespread occurrence and clear potential as a source of DNA, genetic information has not previously been recovered directly from footprints. Here, we extract and amplify mitochondrial DNA from a snow footprint, <48-hours old, made by a Swedish Arctic Fox (Alopex lagopus). Our results demonstrate that it is possible to recover Sufficient DNA from recent footprints to accurately type the source of the print, with implications for conservation biology and forensic science.

  • 10.
    Ersmark, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Baryshnikov, Gennady
    Higham, Tom
    Argant, Alain
    Döppes, Doris
    Germonpré, Mietje
    Lidén, Kerstin
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Archaeological Research Laboratory.
    Lipecki, Grzegorz
    Marciszak, Adrian
    Pacher, Martina
    Storå, Jan
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Osteoarchaeological Research Laboratory.
    Sabol, Martin
    Valdiosera, Christina
    Villaluenga, Aritza
    Stewart, John
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Genetic revolutions and northern survival during the last glacial maximum in European brown bearsManuscript (preprint) (Other academic)
  • 11.
    Ersmark, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Klütsch, Cornelya
    Chan, Yvonne
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Sinding-Larsen, Mikkel
    Gilbert, Thomas
    Arvestad, Lars
    Stockholm University, Faculty of Science, Numerical Analysis and Computer Science (NADA).
    Fain, Steven R.
    Illarionova, Natalia
    Oskarsson, Mattias
    Uhlén, Mathias
    Zhang, Ya-Ping
    Savolainen, Peter
    From the past to the present: Wolf phylogeography and demographic history based on the mitochondrial control regionManuscript (preprint) (Other academic)
  • 12.
    Ersmark, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Orlando, Ludovic
    Sandoval-Castellanos, Edson
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Barnes, Ian
    Barnett, Ross
    Stuart, Anthony
    Lister, Adrian
    Dalén, Love
    Swedish Museum of Natural History, Sweden.
    Population demography and genetic diversity in the Pleistocene cave lion2015In: Open Quaternary, ISSN 2055-298X, Vol. 1, no 1, article id 4Article in journal (Refereed)
    Abstract [en]

    With a range that covered most of northern Eurasia and parts of North America, the cave lion (Panthera spelaea) was one of the most widespread carnivores of the Late Pleistocene. Earlier ancient DNA analyses have shown that it is distinct from modern lions, and have suggested a demographic decline in Beringia during marine isotope stage 3 (MIS 3). Here, we further investigate the Late Pleistocene population dynamics in more detail by combining a powerful algorithm that couples MCMC with coalescent simulations under an approximate Bayesian computation framework. We use an ancient DNA dataset of previously published (n = 34) and new radiocarbon dated specimens (n = 14). Phylogenetic and network analyses based on the mitochondrial control region and the ATP8 gene identified two major haplogroups, one of which appears to vanish around 41,000 cal a BP. The approximate Bayesian computation analysis suggested a decline in effective population size (Ne) in Beringia of at least a 2-fold magnitude that began approximately 47,000 cal a BP, followed by an increase in Ne, most likely around 18,000 cal a BP. The cave lion went through a demographic bottleneck during MIS 3, which may have lasted for several tens of thousands of years, and only recovered shortly before the species' extinction. Several other large mammal species display similar declines in genetic diversity in Beringia during MIS 3, suggesting that major environmental changes might have affected megafaunal populations during this time period.

  • 13. Geffen, E.
    et al.
    Kam, Michael
    Hefner, R.
    Hersteinsson, P.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Naturhistoriska riksmuseet, Molekylärsystematik.
    Fuglei, E.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology.
    Adams, J. R.
    Vucetich, J.
    Meier, T. J.
    Mech, L. D.
    von Holdt, B. M.
    Stahler, D. R.
    Wayne, R. K.
    Kin encounter rate and inbreeding avoidance in canids2011In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 20, no 24, p. 5348-5358Article in journal (Refereed)
    Abstract [en]

    Mating with close kin can lead to inbreeding depression through the expression of recessive deleterious alleles and loss of heterozygosity. Mate selection may be affected by kin encounter rate, and inbreeding avoidance may not be uniform but associated with age and social system. Specifically, selection for kin recognition and inbreeding avoidance may be more developed in species that live in family groups or breed cooperatively. To test this hypothesis, we compared kin encounter rate and the proportion of related breeding pairs in noninbred and highly inbred canid populations. The chance of randomly encountering a full sib ranged between 1–8% and 20–22% in noninbred and inbred canid populations, respectively. We show that regardless of encounter rate, outside natal groups mates were selected independent of relatedness. Within natal groups, there was a significant avoidance of mating with a relative. Lack of discrimination against mating with close relatives outside packs suggests that the rate of inbreeding in canids is related to the proximity of close relatives, which could explain the high degree of inbreeding depression observed in some populations. The idea that kin encounter rate and social organization can explain the lack of inbreeding avoidance in some species is intriguing and may have implications for the management of populations at risk

  • 14. Irestedt, Martin
    et al.
    Fjeldså, Jon
    Dalén, Love
    Ericson, Per
    Convergent evolution, habitat shifts and variable diversification rates in the ovenbird-woodcreeper family (Furnariidae)2010In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 9, no 268Article in journal (Refereed)
  • 15. Koren, Lee
    et al.
    Matas, Devorah
    Pečnerová, Patrícia
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Tikhonov, Alexei
    Gilbert, M. Thomas P.
    Geffen, Eli
    Testosterone in ancient hair from an extinct speciesManuscript (preprint) (Other academic)
  • 16.
    Lagerholm, Vendela K.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden; University of St Andrews, UK.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology. University of California Davis, USA.
    Ehrich, Dorothee
    Ims, Rolf A.
    Killengreen, Siw T.
    Abramson, Natalia I.
    Niemaa, Jukka
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Henttonen, Heikki
    Dalén, Love
    Run to the hills: gene flow among mountain areas leads to low genetic differentiation in the Norwegian lemming2017In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 121, no 1, p. 1-14Article in journal (Refereed)
    Abstract [en]

    The endemic Norwegian lemming (Lemmus lemmus) is an icon for cyclic species, famous since the Middle Ages for its enormous population outbreaks and mass movements. Although the drivers behind this cyclicity have been intensively investigated, virtually nothing is known about the extent to which long-distance dispersal during population peaks actually lead to gene flow among mountain tundra areas. In this article, we use nine microsatellite markers to address this question and analyse range-wide genetic diversity and differentiation between Fennoscandian sub-regions. The results revealed a high genetic variation with a surprisingly weak population structure, comparable to that of much larger mammals. The differentiation was mainly characterized as a genetic cline across the species' entire distribution, and results from spatial autocorrelation analyses suggested that gene flow occurs with sufficiently high frequency to create a genetic patch size of 100 km. Further, we found that for the equivalent distances, the southern sub-regions were genetically more similar to each other than those in the north, which indicates that the prolonged periods of interrupted lemming cyclicity recorded in the northern parts of Fennoscandia have led to increased isolation and population differentiation. In summary, we propose that mass movements during peak years act as pulses of gene flow between mountain tundra areas, and that these help to maintain genetic variation and counteract differentiation over vast geographic distances.

  • 17.
    Lindenfors, Patrik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    A monophyletic origin of delayed implantation and its implications2003In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 57, p. 1952-1956Article in journal (Refereed)
  • 18.
    Naud, Lucy
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Måsviken, Johannes
    Stockholm University, Faculty of Science, Department of Zoology.
    Freire, Susana
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Dalerum, Fredrik
    Stockholm University, Faculty of Science, Department of Zoology. Oviedo University, Spain; University of Pretoria, South Africa.
    Altitude effects on spatial components of vascular plant diversity in a subarctic mountain tundra2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 8, p. 4783-4795Article in journal (Refereed)
    Abstract [en]

    Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences.

  • 19.
    Nielsen, Jens M.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Fussilli, Matteo
    Esparza-Salas, Rodrigo
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Dahlén, Love
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Winder, Monika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Marine zooplankton diet preferences across species, life stages and seasons using DNA barcodingManuscript (preprint) (Other academic)
  • 20.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carmichael, Lindsey
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Hersteinsson, Páll
    Samelius, Gustaf
    Fuglei, Eva
    Kapel, Christian M. O.
    Menyushina, Irina
    Strobeck, Curtis
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Arctic fox Vulpes lagopus population structure: circumpolar patterns and processes2011In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 120, no 6, p. 873-885Article in journal (Refereed)
    Abstract [en]

    Movement is a prominent process shaping genetic population structure. In many northern mammal species, population structure is formed by geographic distance, geographical barriers and various ecological factors that influence movement over the landscape. The Arctic fox Vulpes lagopus is a highly mobile, opportunistic carnivore of the Arctic that occurs in two main ecotypes with different ecological adaptations. We assembled microsatellite data in 7 loci for 1834 Arctic foxes sampled across their entire distribution to describe the circumpolar population structure and test the impact of (1) geographic distance, (2) geographical barriers and (3) ecotype designation on the population structure. Both Structure and Geneland demonstrated distinctiveness of Iceland and Scandinavia whereas low differentiation was observed between North America-northern Greenland, Svalbard and Siberia. Genetic differentiation was significantly correlated to presence of sea ice on a global scale, but not to geographical distance or ecotype designation. However, among areas connected by sea ice, we recorded a pattern of isolation by distance. The maximum likelihood approach in Migrate suggested that connectivity across North America-northern Greenland and Svalbard was particularly high. Our results demonstrate the importance of sea ice for maintaining connectivity between Arctic fox populations and we therefore predict that climate change will increase genetic divergence among populations in the future.

  • 21.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Flagstad, Øystein
    Berteaux, Dominique
    Wallén, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Evolution, ecology and conservation—revisiting three decades of Arctic fox population genetic research2017In: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 36, no suppl. 1, article id 4Article in journal (Refereed)
    Abstract [en]

    Three decades have passed since the Arctic fox (Vulpes lagopus) was first put into a population genetic perspective. With the aim of addressing how microevolution operates on different biological levels, we here review genetic processes in the Arctic fox at the level of species, populations and individuals. Historical and present dispersal patterns, especially in the presence of sea ice, are the most powerful factors that create a highly homogeneous genetic structure across the circumpolar distribution, with low detectable divergence between the coastal and lemming ecotypes. With dispersal less pronounced or absent, other processes emerge; populations that are currently isolated, for example, because of the lack of sea ice, are genetically divergent. Moreover, small populations generally display signatures of genetic drift, inbreeding, inbreeding depression and, under specific situations, hybridization with domestic fox breeds. Mating system and social organization in the Arctic fox appear to be determined by the ecological context, with complex mating patterns and social groups being more common under resource-rich conditions. In isolated populations, complex social groups and inbreeding avoidance have been documented. We emphasize the value of genetic data to decipher many previously unknown aspects of Arctic fox biology, while these data also raise numerous questions that remain unanswered. Pronounced intra-specific ecological variation makes the Arctic fox an ideal study organism for population genetic processes and the emergence of functional genomics will generate an even deeper understanding of evolution, ecology and conservation issues for several species.

  • 22.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Godoy, Erika
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology. National Veterinary Institute, Sweden.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Inbreeding depression in a critically endangered carnivore2016In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, no 14, p. 3309-3318Article in journal (Refereed)
    Abstract [en]

    Harmful effects arising from matings between relatives (inbreeding) is a long-standing observation that is well founded in theory. Empirical evidence for inbreeding depression in natural populations is however rare because of the challenges of assembling pedigrees supplemented with fitness traits. We examined the occurrence of inbreeding and subsequent inbreeding depression using a unique data set containing a genetically verified pedigree with individual fitness traits for a critically endangered arctic fox (Vulpes lagopus) population. The study covered nine years and was comprised of 33 litters with a total of 205 individuals. We recorded that the present population was founded by only five individuals. Over the study period, the population exhibited a tenfold increase in average inbreeding coefficient with a final level corresponding to half-sib matings. Inbreeding mainly occurred between cousins, but we also observed two cases of full-sib matings. The pedigree data demonstrated clear evidence of inbreeding depression on traditional fitness traits where inbred individuals displayed reduced survival and reproduction. Fitness traits were however differently affected by the fluctuating resource abundande. Inbred individuals born at low-quality years displayed reduced first-year survival, while inbred individuals born at high-quality years were less likely to reproduce. The documentation of inbreeding depression in fundamental fitness traits suggests that inbreeding depression can limit population recovery. Introducing new genetic material to promote a genetic rescue effect may thus be necessary for population long-term persistence.

  • 23.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hersteinsson, Pall
    Samelius, Gustaf
    Eide, Nina E.
    Fuglei, Eva
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    From monogamy to complexity: social organization of arctic foxes (Vulpes lagopus) in contrasting ecosystems2012In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 90, no 9, p. 1102-1116Article in journal (Refereed)
    Abstract [en]

    Canids display pronounced intraspecific variation in social organization, ranging from single breeding females to large and complex groups. Despite several hypotheses in this matter, little is understood about the ecological factors underlying this flexibility. We have used the arctic fox (Vulpes lagopus (L., 1758)) to investigate how contrasting ecosystem conditions concerning resources and predation influence group formation. We predicted that complex groups are more common in resource-rich ecosystems with predators, whereas simple groups occur in more marginal ecosystems without predators. Samples from 54 groups were collected from four populations of arctic foxes with contrasting prey resources and predation and these samples were genotyped in 10 microsatellite loci. We found considerable variation between ecosystems and a significant relationship between resources and formation of complex groups. We conclude that sufficient amounts of food is a prerequisite for forming complex groups, but that defense against predation further increases the benefits of living in larger groups. We present a conceptual model suggesting that a trade-off between the cost of resource depletion and the benefits obtained for guarding against predators explain the differences in social organization. The variable ecology of  the arctic foxes makes it is a plausible model species for understanding the connection between ecology and social organization also in other species.

  • 24.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hersteinsson, Páll
    Samelius, Gustaf
    Eide, Nina E.
    Fuglei, Eva
    Elmhagen, Bodil
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Meijer, Tomas
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    From monogamy to complexity: Arctic fox social organizationManuscript (preprint) (Other academic)
  • 25.
    Norén, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kvaloy, Kirsti
    Nyström, Veronica
    Stockholm University, Faculty of Science, Department of Zoology.
    Landa, Arild
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Eide, Nina E.
    Ostbye, Eivind
    Henttonen, Heikki
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Farmed arctic foxes on the Fennoscandian mountain tundra: implications for conservation2009In: Animal Conservation, ISSN 1367-9430, E-ISSN 1469-1795, Vol. 12, no 5, p. 434-444Article in journal (Refereed)
    Abstract [en]

    Hybridization between wild and captive-bred individuals is a serious conservation issue that requires measures to prevent negative effects. Such measures are, however, often considered controversial by the public, especially when concerning charismatic species. One of the threats to the critically endangered Fennoscandian arctic fox Alopex lagopus is hybridization with escaped farm foxes, conveying a risk of outbreeding depression through loss of local adaptations to the lemming cycle. In this study, we investigate the existence of escaped farm foxes among wild arctic foxes and whether hybridization has occurred in the wild. We analysed mitochondrial control region sequences and 10 microsatellite loci in samples from free-ranging foxes and compared them with reference samples of known farm foxes and true Fennoscandian arctic foxes. We identified the farm fox specific mitochondrial haplotype H9 in 25 out of 182 samples, 21 of which had been collected within or nearby the wild subpopulation on Hardangervidda in south-western Norway. Genetic analyses of museum specimens collected on Hardangervidda (1897–1975) suggested that farm fox genotypes have recently been introduced to the area. Principal component analysis as well as both model- and frequency-based analyses of microsatellite data imply that the free-ranging H9s were farm foxes rather than wild arctic foxes and that the entire Hardangervidda population consisted of farm foxes or putative hybrids. We strongly recommend removal of farm foxes and hybrids in the wild to prevent genetic pollution of the remaining wild subpopulations of threatened arctic foxes.

  • 26.
    Nyström, Jesper
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Ekenstedt, Johan
    Angleby, Helen
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Effect of local prey availability on gyrfalcon diet: DNA analysis on ptarmigan remains at nest sites2006In: Journal of Zoology, ISSN 0952-8369, E-ISSN 1469-7998, Vol. 269, no 1, p. 57-64Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate how the diet of gyrfalcon Falco rusticolus in northern Sweden was affected by the relative availability of its two main prey species: rock ptarmigan Lagopus mutus and willow ptarmigan Lagopus lagopus. In order to do so, we needed a method to estimate the gyrfalcon's diet proportions of rock and willow ptarmigan from prey remains that we collected from nest sites in separate breeding territories. We also needed a method to calculate the availability of the two prey species in the same breeding territories that the prey remains originated from. We could then compare the diet proportions with prey availability and investigate if the gyrfalcons utilized the two species strictly in relation to their densities, or if they showed a preference for any of the prey species. Morphometric identification to species level from ptarmigan remains was not possible. Therefore, we developed a PCR-based process of DNA analysis, which could be applied on any ptarmigan bone or bone remains. This method allowed us to establish the ratio of rock and willow ptarmigan in gyrfalcon diets that originated from single gyrfalcon breeding occasions. The relative availability of the two ptarmigan species in gyrfalcon breeding territories was calculated with a GIS model that incorporated observations on ptarmigan habitat preferences. The DNA identification was performed on 176 ptarmigan bones from 13 different breeding occasions occurring in five different territories. The results indicated that the two ptarmigan species comprised at least 93% of the average gyrfalcon diet, and that rock ptarmigan was the most common prey during all 13 breeding occasions. There was a positive relationship between the relative amount of rock ptarmigan in the diet and the proportion of rock ptarmigan habitat in the territories; hence, the gyrfalcons ptarmigan utilization seemed to be density dependent. However, rock ptarmigan was found to be overrepresented in the diet, which may reflect a preference for rock ptarmigan over willow ptarmigan. The conservation implications of these findings in relation to ptarmigan hunting are discussed.

  • 27.
    Nyström, Jesper
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Ekenstedt, Johan
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Thulin, Linda
    Stockholm University, Faculty of Science, Department of Zoology.
    Hellström, Peter
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Golden Eagles on the Swedish mountain tundra - diet and breeding success in relation to prey fluctuations2006In: Ornis Fennica, ISSN 0030-5685, Vol. 83, no 4, p. 145-152Article in journal (Refereed)
    Abstract [en]

    We studied the diet and the relationship between prey density fluctuations and breeding success of a Golden Eagle (Aquila chrysaetos) population on the mountain tundra region of northern Sweden. We used a new PCR based method to analyse the DNA in bone fragments from Golden Eagle prey remains. This allowed us to accurately identify the Ptarmigan species that the bone fragments originated from, and hence, establish the proportions of Ptarmigan species in the eagle's diet. We could conclude that Ptarmigan species (Lagopus spp.) are the most important prey category for this Golden Eagle population (63% of all identified prey), and that Willow Ptarmigan (L. lagopus) occurred more frequently in the diet than Rock Ptarmigan (L. mutus) did (Willow Ptarmigan 38%, Rock Ptarmigan 25%). Other important prey included reindeer (Rang fer tarandus), mountain hare (Lepus timidus) and microtine rodents. The Golden Eagles managed to maintain a relatively broad food niche, despite an environment with low prey diversity. Microtine rodents, hare and Ptarmigan populations showed similar population fluctuations in the study area. The breeding success of the Golden Eagles showed a strong relationship to the yearly density index of the most important prey category, the Ptarmigan species.

  • 28.
    Nyström, Veronica
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Genetic consequences of a demographic bottleneck in the Scandinavian arctic fox2006In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 114, no 1, p. 84-94Article in journal (Refereed)
    Abstract [en]

    Demographic bottlenecks can result in a loss of genetic variation due to the bottleneck effect and subsequent genetic drift. The arctic fox population in Scandinavia went through a severe demographic bottleneck in the early 20th century, and is today classified as critically endangered. In this study, we investigated the pre-bottleneck genetic variation in Scandinavia and compared it to modern samples from Scandinavia and North Russia. Variation in the mtDNA control region and five microsatellite loci was examined through ancient DNA analysis on museum specimens. The microsatellite data from the museum specimens was further used to simulate the expected effect of the bottleneck. The arctic foxes in Scandinavia have lost approximately 25% of the microsatellite alleles and four out of seven mtDNA haplotypes. The results also suggest that the genetic differentiation between North Russia and Scandinavia has doubled over the last 100 years. However, the level of heterozygosity was significantly higher than expected from the simulations. This highlights both the advantage of using museum specimens and the importance of generating specific predictions in conservation genetics.

  • 29.
    Nyström, Veronica
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Vartanyan, Sergey
    Department of Geography, Herzen University, nab. Moyki, 48, St Petersburg.
    Lidén, Kerstin
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Temporal genetic change in the last remaining population of woolly mammoth2010In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 277, no 1692, p. 2331-2337Article in journal (Refereed)
    Abstract [en]

    During the Late Pleistocene, the woolly mammoth (Mammuthus primigenius) experienced a series of local extinctions generally attributed to human predation or environmental change. Some small and isolated populations did however survive far into the Holocene. Here, we investigated the genetic consequences of the isolation of the last remaining mammoth population on Wrangel Island. We analysed 741 bp of the mitochondrial DNA and found a loss of genetic variation in relation to the isolation event, probably caused by a demographic bottleneck or a founder event. However, in spite of ca 5000 years of isolation, we did not detect any further loss of genetic variation. Together with the relatively high number of mitochondrial haplotypes on Wrangel Island near the final disappearance, this suggests a sudden extinction of a rather stable population.

  • 30.
    Nyström, Veronica
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Humphrey, Joanne
    Skoglund, Pontus
    McKeown, Niall
    Jakobsson, Mattias
    Vartanyan, Sergey
    Lidén, Kerstin
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Barnes, Ian
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Lister, Adrian
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Microsatellite genotyping reveals end-Pleistocene shift in mammoth autosomal genetic variationManuscript (preprint) (Other academic)
  • 31.
    Palkopoulou, Eleftheria
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Baca, Mateusz
    Abramson, Natalya
    Socha, Pavel
    Nadakowski, Adam
    Prost, Stefan
    Germonpré, Metje
    Kosintsev, Pavel
    Smirnov, Nickolay
    Vartanyan, Sergey
    Ponomarev, Dmitry
    Nyström, Johanna
    Nikolskiy, Pavel
    Jass, Chris
    Yuriy, Litvinov
    Kalthoff, Daniela
    Grigoriev, Semyon
    Fadeeva, Tatyana
    Higham, Thomas
    Ersmark, Erik
    Stockholm University, Faculty of Science, Department of Zoology.
    Stewart, John
    Weglénski, Piotr
    Stankovic, Anna
    Dalén, Love
    Palaeogenetic analyses reveal wide-spread Pleistocene range fluctuations in the collared lemmingManuscript (preprint) (Other academic)
  • 32.
    Palkopoulou, Eleftheria
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Mallick, Swapan
    Skoglund, Pontus
    Enk, Jacob
    Rohland, Nadin
    Li, Heng
    Omrak, Ayca
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Vartanyan, Sergey
    Poinar, Hendrik
    Götherström, Anders
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Reich, David
    Dalén, Love
    Genome-wide signatures of demographic change and Holocene genetic decline in the extinct woolly mammothManuscript (preprint) (Other academic)
  • 33.
    Pečnerová, Patrícia
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Díez-Del-Molino, David
    Palkopoulou, Eleftheria
    Skoglund, Pontus
    Tikhonov, Alexei
    Nikolskiy, Pavel
    Vartanyan, Sergey
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Pre-extinction population dynamics and genome erosion in the woolly mammothManuscript (preprint) (Other academic)
  • 34. Smith, Steve
    et al.
    Sandoval-Castellanos, Edson
    Kempe Lagerholm, Vendela
    Stockholm University, Faculty of Science, Department of Zoology.
    Napierala, Hannes
    Sablin, Michael
    Nyström, Johanna
    Fladerer, Florian A.
    Germonpré, Mietje
    Wojtal, Piotr
    Stewart, John R.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Non-receding hare lines: genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)Manuscript (preprint) (Other academic)
  • 35. Stewart, John
    et al.
    Lister, Adrian
    Barnes, Ian
    Dalén, Love
    Refugia revisited: individualistic responses of species in space and time2010In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 277, p. 661-671Article in journal (Refereed)
    Abstract [en]

    Climate change in the past has led to significant changes in species' distributions. However, how individual species respond to climate change depends largely on their adaptations and environmental tolerances. In the Quaternary, temperate-adapted taxa are in general confined to refugia during glacials while cold-adapted taxa are in refugia during interglacials. In the Northern Hemisphere, evidence appears to be mounting that in addition to traditional southern refugia for temperate species, cryptic refugia existed in the North during glacials. Equivalent cryptic southern refugia, to the south of the more conventional high-latitude polar refugia, exist in montane areas during periods of warm climate, such as the current interglacial. There is also a continental/oceanic longitudinal gradient, which should be included in a more complete consideration of the interaction between species ranges and climates. Overall, it seems clear that there is large variation in both the size of refugia and the duration during which species are confined to them. This has implications for the role of refugia in the evolution of species and their genetic diversity.

  • 36.
    Särnblad, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Kiszka, Jeremy
    Collins, Tim
    Amir, Omar A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Berggren, Per
    Stockholm University, Faculty of Science, Department of Zoology.
    Population structure and diversity of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the western Indian OceanManuscript (preprint) (Other academic)
    Abstract [en]

    Bottlenose dolphin (Tursiops sp.) populations often show small-scale genetic differentiation and have a capacity to adapt both their social strategies and structure to local environmental conditions. Here we investigate population structure and genetic diversity of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the western Indian Ocean, with special reference to Zanzibar, Tanzania. The Indo-Pacific bottlenose dolphins off Zanzibar were previously hunted and are subject to high levels of bycatch and negative impact from tourism. A recent study has indicated a limited exchange of reproducing females between northern and southern Zanzibar. Mitochondrial DNA sequence (mtDNA 429bp) variation and autosomal genotypes (7 microsatellite loci) was used to assess genetic variation and differentiation among tissue samples from Zanzibar (n=91) Mayotte (n=12) and Oman (n=4). The results showed a much higher amount of differentiation for mtDNA than autosomal DNA between northern and southern Zanzibar suggesting female philopatry with greater dispersal by males than females. Genetic diversity levels were relatively high in all areas and there were no indications of any recent reduction in effective population size, except in Mayotte where indications of a recent bottleneck encourage further analyses. Further, the close relationship and lack of clear structuring, with several shared haplotypes among regions, suggest a relatively recent common founder population for the Indo-Pacific bottlenose dolphins in the western Indian Ocean. Based on the high differentiation in mtDNA between northern and southern Zanzibar and that local growth rates in large part will be determined by female breeding success, we suggest that the Indo-Pacific bottlenose dolphins off northern and southern Zanzibar should be treated as separate management units.

  • 37.
    Särnblad, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Danbolt, Magnus
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology.
    Amir, Omar A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Berggren, Per
    Stockholm University, Faculty of Science, Department of Zoology.
    Phylogenetic placement and population structure of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Zanzibar, Tanzania, based on mtDNA sequences2011In: Marine mammal science, ISSN 0824-0469, E-ISSN 1748-7692, Vol. 27, no 2, p. 431-448Article in journal (Refereed)
    Abstract [en]

    Phylogenetic placement of bottlenose dolphins from Zanzibar, East Africa and putative population differentiation between animals found off southern and northern Zanzibar were examined using variation in mtDNA control region sequences. Samples (n= 45) from animals bycaught in fishing gear and skin biopsies collected during boat surveys were compared to published sequences (n= 173) of Indo-Pacific bottlenose dolphin, Tursiops aduncus, from southeast Australian waters, Chinese/Indonesian waters, and South African waters (which recently was proposed as a new species) and to published sequences of common bottlenose dolphin, Tursiops truncatus. Bayesian and maximum parsimony analyses indicated a close relationship between Zanzibar and South African haplotypes, which are differentiated from both Chinese/Indonesian and Australian T. aduncus haplotypes. Our results suggest that the dolphins found off Zanzibar should be classified as T. aduncus alongside the South African animals. Further, analyses of genetic differentiation showed significant separation between the T. aduncus found off northern and southern Zanzibar despite the relatively short distance (approximately 80 km) between these areas. Much less differentiation was found between southern Zanzibar and South Africa, suggesting a more recent common evolutionary history for these populations than for the northern and southern Zanzibar populations.

  • 38.
    Tison, Jean-Luc
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Chan, Yvonne
    Dalén, Love
    Planes, Serge
    Indo-Pacific population genetic  structure and demographic history of a highly abundant and widespread coral reef fish, Acanthurus triostegusManuscript (preprint) (Other academic)
  • 39.
    Tison, Jean-Luc
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Swedish Museum of National History, Sweden.
    Nyström Edmark, Veronica
    Sandoval-Castellanos, Edson
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of National History, Sweden.
    Van Dyck, Hans
    Tammaru, Toomas
    Valimäki, Panu
    Dalén, Love
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Signature of post-glacial expansion and genetic structure at the northern range limit of the speckled wood butterfly2014In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 113, no 1, p. 136-148Article in journal (Refereed)
    Abstract [en]

    The post-glacial recolonisation of northern Europe has left distinct signatures in the genomes of many organisms, both due to random demographic processes and divergent natural selection. However, information on differences in genetic variation in conjunction with patterns of local adaptations along latitudinal gradients is often lacking. In this study, we examine genetic diversity and population structure in the speckled wood butterfly Pararge aegeria in northern Europe to investigate the species post-glacial recolonisation history and discuss how this may have affected its life-history evolution. We collected 209 samples and analysed genetic variation in nine microsatellite loci. The results demonstrated a more pronounced population structure in northern Europe compared with populations further south, as well as an overall decrease in genetic diversity with latitude, likely due to founder effects during the recolonisation process. Coalescent simulations coupled with approximate Bayesian computation suggested that central Scandinavia was colonised from the south, rather than from the east. In contrast to further south, populations at the northern range margin are univoltine expressing only one generation per year. This suggests either that univoltinism evolved independently on each side of the Baltic Sea, or that bivoltinism evolved in the south after northern Europe was recolonised.

  • 40.
    Valdiosera, C.
    et al.
    Centro UCM-ISCIII de Evolucio´n y Comportamiento Humanos,C/Sinesio Delgado 4, 28029 Madrid, Spain.
    Garcia, N.
    Centro UCM-ISCIII de Evolucio´n y Comportamiento Humanos,C/Sinesio Delgado 4, 28029 Madrid, Spain.
    Dalen, L.
    Stockholm University, Faculty of Science, Department of Zoology.
    Smith, C.
    Departamento de Paleobiologı´a, Museo Nacional de Ciencias Naturales.
    Kahlke, R. D.
    Forschungsstation für Quartärpalä ontologie Weimar, ForschungsinstitutSenckenberg, Am Jakobskirchhof 4, 99423 Weimar, Germany.
    Liden, K.
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies. Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Archaeological Research Laboratory.
    Angerbjörn, A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Arsuaga, J. L.
    Centro UCM-ISCIII de Evolucio´n y Comportamiento Humanos,C/Sinesio Delgado 4, 28029 Madrid, Spain.
    Götherström, A.
    Department of Evolutionary Biology, Uppsala University.
    Typing single polymorphic nucleotides in mitochondrial DNA as a way to access Middle Pleistocene DNA2006In: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 2, no 4, p. 601-603Article in journal (Refereed)
    Abstract [en]

    In this study, we have used a technique designed to target short fragments containing informative mitochondrial substitutions to extend the temporal limits of DNA recovery and study the molecular phylogeny of Ursus deningeri. We present a cladistic analysis using DNA recovered from 400 kyr old U. deningeri remains, which demonstrates U. deningeri's relation to Ursus spelaeus. This study extends the limits of recovery from skeletal remains by almost 300 kyr. Plant material from permafrost environments has yielded DNA of this age in earlier studies, and our data suggest that DNA in teeth from cave environments may be equally well preserved.

  • 41.
    Xenikoudakis, Georgios
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of National History, Sweden.
    Ersmark, Erik
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of National History, Sweden.
    Tison, J. -L.
    Waits, L.
    Kindberg, J.
    Swenson, J. E.
    Dalén, Love
    Swedish Museum of National History, Sweden.
    Consequences of a demographic bottleneck on geneticstructure and variation in the Scandinavian brown bear2015In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 24, no 13, p. 3441-3454Article in journal (Refereed)
    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.

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