| 1. |
- Bergström, Anders, et al.
(författare)
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Grey wolf genomic history reveals a dual ancestry of dogs
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 607:7918, s. 313-320
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Tidskriftsartikel (refereegranskat)abstract
- The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.
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| 2. |
- Bergström, Anders, et al.
(författare)
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Origins and genetic legacy of prehistoric dogs
- 2020
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 370:6516, s. 557-563
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Tidskriftsartikel (refereegranskat)abstract
- Dogs were the first domestic animal, but little is known about their population history and to what extent it was linked to humans. We sequenced 27 ancient dog genomes and found that all dogs share a common ancestry distinct from present-day wolves, with limited gene flow from wolves since domestication but substantial dog-to-wolf gene flow. By 11,000 years ago, at least five major ancestry lineages had diversified, demonstrating a deep genetic history of dogs during the Paleolithic. Coanalysis with human genomes reveals aspects of dog population history that mirror humans, including Levant-related ancestry in Africa and early agricultural Europe. Other aspects differ, including the impacts of steppe pastoralist expansions in West and East Eurasia and a near-complete turnover of Neolithic European dog ancestry.
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| 3. |
- van der Valk, Tom, et al.
(författare)
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Million-year-old DNA sheds light on the genomic history of mammoths
- 2021
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 591:7849, s. 265-269
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Tidskriftsartikel (refereegranskat)abstract
- Temporal genomic data hold great potential for studying evolutionary processes such as speciation. However, sampling across speciation events would, in many cases, require genomic time series that stretch well back into the Early Pleistocene subepoch. Although theoretical models suggest that DNA should survive on this timescale1, the oldest genomic data recovered so far are from a horse specimen dated to 780–560 thousand years ago2. Here we report the recovery of genome-wide data from three mammoth specimens dating to the Early and Middle Pleistocene subepochs, two of which are more than one million years old. We find that two distinct mammoth lineages were present in eastern Siberia during the Early Pleistocene. One of these lineages gave rise to the woolly mammoth and the other represents a previously unrecognized lineage that was ancestral to the first mammoths to colonize North America. Our analyses reveal that the Columbian mammoth of North America traces its ancestry to a Middle Pleistocene hybridization between these two lineages, with roughly equal admixture proportions. Finally, we show that the majority of protein-coding changes associated with cold adaptation in woolly mammoths were already present one million years ago. These findings highlight the potential of deep-time palaeogenomics to expand our understanding of speciation and long-term adaptive evolution.
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| 4. |
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| 5. |
- Bergström, Anders, 1965-, et al.
(författare)
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Millesgården : Arkitektur & trädgård
- 2004
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Bok (refereegranskat)abstract
- Millesgården på Lidingö norr om Stockholm är ett av Sveriges mest välkända konstnärshem. Här uppförde skulptören Carl Milles från 1908 en kombinerad ateljé och bostad med anslutande trädgård. Trots att Milles var en mycket produktiv och framgångsrik skulptör, finns det skäl att framhålla Millesgården som hans främsta konstnärliga arbete.Millesgårdens tillkomst skildras här i nära anslutning till den samtida utvecklingen inom arkitektur och trädgårdskonst. Anläggningen fungerade inte bara som hem och ateljé, utan även som utställningsmiljö. Millesgården blev ett monument – en minnesgård – där Carl Milles ambitioner och höga anspråk på konstnärsrollen kom till uttryck.
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| 6. |
- Bergström, Anders
(författare)
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Oviposition site preferences of the threatened butterfly Parnassius mnemosyne : implications for conservation
- 2005
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Ingår i: Journal of Insect Conservation. - : Springer. - 1366-638X .- 1572-9753. ; 9:1, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies on the threatened clouded apollo butterfly, Parnassius mnemosyne, have identified suitable habitats on a large scale. More detailed knowledge on specific habitat requirements of ovipositing females is still needed. Some earlier observations suggest that females just drop their eggs without discrimination. This study suggests that females can be rather choosy in their oviposition site selection and that they actively search for oviposition sites with suitable vegetation structure. By identifying factors influencing female oviposition, such as distance to shrub, valuable knowledge is generated for restoration plans considered in the study area. This stresses the importance of proper management of extant habitats in order to prevent local extinctions of P. mnemosyne and it also highlights the need for data on specific oviposition requirements in butterfly conservation.
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| 7. |
- Bergström, Anders, 1969-
(författare)
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Oviposition strategies in butterflies and consequences for conservation
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Oviposition strategies are an important component of life history evolution in insects. Oviposition is a complex behaviour, where females must locate suitable habitat patches, locate oviposition sites, evaluate the quality, and finally decide how many eggs to lay. In this thesis, I explore some factors that may influence oviposition strategies in female butterflies. It discusses oviposition strategies from large to fine scales and ends with a discussion on implications for conservation. In paper I we tested for local adaptations in oviposition preference and larval performance in Polyommatus icarus. The result suggests that this species is evolutionary conservative in its utilization of the tested host plants. In the second paper we investigated frequency-dependent host plant choice in Polygonia c-album and showed that females spent significantly more time, and laid more eggs, in patches with high frequency of the preferred host. The influence of nectar sources on host plant choice in P. icarus was tested in paper III, females preferred ovipositing on host plants with flowers and after feeding. In paper IV we investigated oviposition “mistakes” in P. c-album and found differences in discrimination of hosts and non-hosts. Further, we showed that P. c-album butterflies are capable of responding to host quality by increasing clutch sizes on a high ranked host (paper V). Finally, in paper VI I explored how female oviposition behaviour can influence habitat management for a threatened butterfly species, Parnassius mnemosyne, by doing an observational field study on oviposition site preferences. This thesis highlights oviposition as a stepwise process and show that female discrimination is important at a multitude of levels with implications for oviposition strategies.
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| 8. |
- Bergström, Anders, et al.
(författare)
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Putting more eggs in the best basket : clutch size regulation in the comma butterfly
- 2006
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Ingår i: Ecological Entomology. - : Wiley. - 0307-6946 .- 1365-2311. ; 31:3, s. 255-260
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Tidskriftsartikel (refereegranskat)abstract
- 1. Many studies have identified different factors influencing clutchsize regulation, primarily within various groups of insects. One prediction is that ovipositing females should increase clutch size with host quality. However, in many studies it is not clear whether ovipositing females are responding to host quality or quantity. 2. Females of the polyphagous comma butterfly, allowed to oviposit on two hosts differing greatly in quality: the preferred host, stinging nettle (Polygonia c-album (L.), wereUrtica dioica L.), and the low-ranked host, birch (Betula pubescens Ehrh). Ovipositing females were observed visually and clutch sizes were recorded. The experiment was repeated in three different years; in total, 938 observations of oviposition events were made. 3. In all three years, females ovipositing on (median 1.6–1.85) compared with females ovipositing on 1.0–1.3) three years were pooled. 4. Thus, on better hosts. It is suggested that the proximate mechanism is likely to be a response to the same stimuli used for female ranking of host plants in the preference hierarchy. U. dioica laid larger clutchesB. pubescens (median. The difference was significant in two out of three years and when allP. c-album females exhibit clutch-size regulation, with larger clutches
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| 9. |
- Bergström, Göran, et al.
(författare)
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Idé- och ideologianalys
- 2018. - 4
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Ingår i: Textens mening och makt. - Lund : Studentlitteratur AB. - 9789144117928 ; , s. 125-168
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Bergström, Malin, et al.
(författare)
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Children with two homes: Psychological problems in relation to living arrangements in Nordic 2-to 9-year-olds
- 2019
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Ingår i: Scand J Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 47:2, s. 137-145
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Joint physical custody, children spending equal time in each parents' respective home after a parental divorce, is particularly common in Nordic compared with other Western countries. Older children have been shown to fare well in this practice but for young children there are few existing studies. The aim of this paper is to study psychological problems in 2- to 9-year-old Nordic children in different family forms. Methods: Total symptom score according to the Strengths and Difficulties Questionnaire as well as scores showing externalizing problems were compared among 152 children in joint physical custody, 303 in single care and 3207 in nuclear families through multiple linear regression analyses. Results: Children in single care had more psychological symptoms than those in joint physical custody (B = 1.08; 95% CI 0.48 to 1.67) and those in nuclear families had the least reported symptoms (B = -0.53; 95% CI -0.89 to -0.17). Externalizing problems were also lower in nuclear families (B = -0.28, 95% CI -0.52 to -0.04) compared with joint physical custody after adjusting for covariates. Conclusions: Young children with non-cohabiting parents suffered from more psychological problems than those in intact families. Children in joint physical custody had a lower total problem score than those in single care after adjusting for covariates. Longitudinal studies with information on family factors before the separation are needed to inform policy of young children's post-separation living arrangements.
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