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- Fayle, Tom M, et al.
(författare)
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A positive relationship between ant biodiversity (Hymenoptera: Formicidae) and rate of scavenger-mediated nutrient redistribution along a disturbance gradient in a south-east Asian rain forest
- 2011
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Ingår i: MYRMECOLOGICAL NEWS. - : OESTERREICHISCHE GESELL ENTOMOFAUNISTIK, C/O NATURHISTOR MUSEUM WIEN, ZWEITE ZOOLOGISCHE ABTEILUNG (INSEKTEN), BURGRING 7, WIEN, AUSTRIA. - 1994-4136. ; 14, s. 5-12
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Tidskriftsartikel (refereegranskat)abstract
- Human modification of pristine habitats almost always leads to the local extinction of a subset of the species present. This means that the ecosystem processes carried out by the remaining species may change. It is well documented that particular species of ants carry out important ecosystem processes. However, while much work has been carried out to investigate the link between biodiversity and ecosystem functioning in other taxa, this has received relatively little attention for ant communities. In particular, no attempt has been made to link levels of ant diversity with the rates of nutrient redistribution carried out by scavenging species. Here we investigate the impacts of anthropogenic disturbance on the rate of scavenger-mediated nutrient redistribution, using bait-removal rate as a surrogate measure. We found that although ant species richness, diversity, biomass and rates of bait removal did not change systematically across the disturbance gradient, the rate of bait removal was related to ant species richness. Sites with more ant species experienced a faster rate of bait removal. This is the first documented positive relationship between ant species richness and the rate of an ecosystem process. If these results are applicable at larger spatial scales for a wider range of nutrient sources, loss of ant species could lead to important changes in the way that ecosystems function.
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| 3. |
- Zeng, Yu, et al.
(författare)
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Sexual selection impacts brain anatomy in frogs and toads
- 2016
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:19, s. 7070-7079
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Tidskriftsartikel (refereegranskat)abstract
- Natural selection is a major force in the evolution of vertebrate brain size, but the role of sexual selection in brain size evolution remains enigmatic. At least two opposing schools of thought predict a relationship between sexual selection and brain size. Sexual selection should facilitate the evolution of larger brains because better cognitive abilities may aid the competition for mates. However, it may also restrict brain size evolution due to energetic trade-offs between brain tissue and sexually selected traits. Here, we examined the patterns of selection on brain size and brain anatomy in male anurans (frogs and toads), a group where the strength of sexual selection differs markedly among species, using a phylogenetically controlled generalized least-squared (PGLS) regression analyses. The analysis revealed that in 43 Chinese anuran species, neither mating system, nor type of courtship, or testes mass was significantly associated with relative brain size. While none of those factors related to the relative size of olfactory nerves, optic tecta, telencephalon, and cerebellum, the olfactory bulbs were relatively larger in monogamous species and those using calls during courtship. Our findings support the mosaic model of brain evolution and suggest that while the investigated aspects of sexual selection do not seem to play a prominent role in the evolution of brain size of anurans, they do impact their brain anatomy.
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