| 1. |
- Calatayud, Joaquín, et al.
(författare)
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Positive associations among rare species and their persistence in ecological assemblages
- 2020
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Ingår i: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 4:1, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- According to the competitive exclusion principle, species with low competitive abilities should be excluded by more efficient competitors; yet, they generally remain as rare species. Here, we describe the positive and negative spatial association networks of 326 disparate assemblages, showing a general organization pattern that simultaneously supports the primacy of competition and the persistence of rare species. Abundant species monopolize negative associations in about 90% of the assemblages. On the other hand, rare species are mostly involved in positive associations, forming small network modules. Simulations suggest that positive interactions among rare species and microhabitat preferences are the most probable mechanisms underpinning this pattern and rare species persistence. The consistent results across taxa and geography suggest a general explanation for the maintenance of biodiversity in competitive environments. Analysing spatial association networks among >300 terrestrial and aquatic assemblages, the authors find that the majority of negative associations involve abundant species. In contrast, rare species form mostly positive associations, potentially explaining their persistence in natural communities.
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| 2. |
- Höglund, Andrey, 1985-, et al.
(författare)
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The methylation landscape and its role in domestication and gene regulation in the chicken
- 2020
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Ingår i: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X. ; 4, s. 1713-1724
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Tidskriftsartikel (refereegranskat)abstract
- Domestication is one of the strongest examples of artificial selection and has produced some of the most extreme within-species phenotypic variation known. In the case of the chicken, it has been hypothesized that DNA methylation may play a mechanistic role in the domestication response. By inter-crossing wild-derived red junglefowl with domestic chickens, we mapped quantitative trait loci for hypothalamic methylation (methQTL), gene expression (eQTL) and behaviour. We find large, stable methylation differences, with 6,179 cis and 2,973 trans methQTL identified. Over 46% of the trans effects were genotypically controlled by five loci, mainly associated with increased methylation in the junglefowl genotype. In a third of eQTL, we find that there is a correlation between gene expression and methylation, while statistical causality analysis reveals multiple instances where methylation is driving gene expression, as well as the reverse. We also show that methylation is correlated with some aspects of behavioural variation in the inter-cross. In conclusion, our data suggest a role for methylation in the regulation of gene expression underlying the domesticated phenotype of the chicken.
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| 3. |
- Libby, Eric
(författare)
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Modularity of the life cycle
- 2019
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Ingår i: Nature Ecology & Evolution. - : NATURE PUBLISHING GROUP. - 2397-334X. ; 3:8, s. 1142-1143
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Life stages in Bacillus subtilis are controlled by regulatory blocks that can be kept or lost across species in response to selection in different environments.
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| 4. |
- MacDougall, Andrew S., et al.
(författare)
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Widening global variability in grassland biomass since the 1980s
- 2024
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Ingår i: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X.
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Tidskriftsartikel (refereegranskat)abstract
- Global change is associated with variable shifts in the annual production of aboveground plant biomass, suggesting localized sensitivities with unclear causal origins. Combining remotely sensed normalized difference vegetation index data since the 1980s with contemporary field data from 84 grasslands on 6 continents, we show a widening divergence in site-level biomass ranging from +51% to −34% globally. Biomass generally increased in warmer, wetter and species-rich sites with longer growing seasons and declined in species-poor arid areas. Phenological changes were widespread, revealing substantive transitions in grassland seasonal cycling. Grazing, nitrogen deposition and plant invasion were prevalent in some regions but did not predict overall trends. Grasslands are undergoing sizable changes in production, with implications for food security, biodiversity and carbon storage especially in arid regions where declines are accelerating.
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| 5. |
- Metcalfe, Daniel B., et al.
(författare)
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Patchy field sampling biases understanding of climate change impacts across the Arctic
- 2018
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Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:9, s. 1443-1448
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Tidskriftsartikel (refereegranskat)abstract
- Effective societal responses to rapid climate change in the Arctic rely on an accurate representation of region-specific ecosystem properties and processes. However, this is limited by the scarcity and patchy distribution of field measurements. Here, we use a comprehensive, geo-referenced database of primary field measurements in 1,840 published studies across the Arctic to identify statistically significant spatial biases in field sampling and study citation across this globally important region. We find that 31% of all study citations are derived from sites located within 50 km of just two research sites: Toolik Lake in the USA and Abisko in Sweden. Furthermore, relatively colder, more rapidly warming and sparsely vegetated sites are under-sampled and under-recognized in terms of citations, particularly among microbiology-related studies. The poorly sampled and cited areas, mainly in the Canadian high-Arctic archipelago and the Arctic coastline of Russia, constitute a large fraction of the Arctic ice-free land area. Our results suggest that the current pattern of sampling and citation may bias the scientific consensuses that underpin attempts to accurately predict and effectively mitigate climate change in the region. Further work is required to increase both the quality and quantity of sampling, and incorporate existing literature from poorly cited areas to generate a more representative picture of Arctic climate change and its environmental impacts.
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| 6. |
- Pineau, Rozenn M., et al.
(författare)
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Emergence and maintenance of stable coexistence during a long-term multicellular evolution experiment
- 2024
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Ingår i: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 8:5, s. 1010-1020
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of multicellular life spurred evolutionary radiations, fundamentally changing many of Earth’s ecosystems. Yet little is known about how early steps in the evolution of multicellularity affect eco-evolutionary dynamics. Through long-term experimental evolution, we observed niche partitioning and the adaptive divergence of two specialized lineages from a single multicellular ancestor. Over 715 daily transfers, snowflake yeast were subjected to selection for rapid growth, followed by selection favouring larger group size. Small and large cluster-forming lineages evolved from a monomorphic ancestor, coexisting for over ~4,300 generations, specializing on divergent aspects of a trade-off between growth rate and survival. Through modelling and experimentation, we demonstrate that coexistence is maintained by a trade-off between organismal size and competitiveness for dissolved oxygen. Taken together, this work shows how the evolution of a new level of biological individuality can rapidly drive adaptive diversification and the expansion of a nascent multicellular niche, one of the most historically impactful emergent properties of this evolutionary transition.
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| 7. |
- Recknagel, Hans, et al.
(författare)
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The functional genetic architecture of egg-laying and live-bearing reproduction in common lizards
- 2021
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Ingår i: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X. ; 5:11, s. 1546-1556
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Tidskriftsartikel (refereegranskat)abstract
- All amniotes reproduce either by egg-laying (oviparity), which is ancestral to vertebrates or by live-bearing (viviparity), which has evolved many times independently. However, the genetic basis of these parity modes has never been resolved and, consequently, its convergence across evolutionary scales is currently unknown. Here, we leveraged natural hybridizations between oviparous and viviparous common lizards (Zootoca vivipara) to describe the functional genes and genetic architecture of parity mode and its key traits, eggshell and gestation length, and compared our findings across vertebrates. In these lizards, parity trait genes were associated with progesterone-binding functions and enriched for tissue remodelling and immune system pathways. Viviparity involved more genes and complex gene networks than did oviparity. Angiogenesis, vascular endothelial growth and adrenoreceptor pathways were enriched in the viviparous female reproductive tissue, while pathways for transforming growth factor were enriched in the oviparous. Natural selection on these parity mode genes was evident genome-wide. Our comparison to seven independent origins of viviparity in mammals, squamates and fish showed that genes active in pregnancy were related to immunity, tissue remodelling and blood vessel generation. Therefore, our results suggest that pre-established regulatory networks are repeatedly recruited for viviparity and that these are shared at deep evolutionary scales. Using natural hybrids between oviparous and viviparous common lizards, the authors describe the genetic architecture of parity mode and conduct a comparative analysis of genes associated with viviparity in mammals, squamates and fish.
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