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- Altizer, Sonia, et al.
(författare)
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Do threatened hosts have fewer parasites? : A comparative study in primates
- 2007
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745 .- 0021-8790 .- 1365-2656. ; 76, s. 304-314
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Tidskriftsartikel (refereegranskat)abstract
- 1. Parasites and infectious diseases have become a major concern in conservation biology, in part because they can trigger or accelerate species or population declines. Focusing on primates as a well-studied host clade, we tested whether the species richness and prevalence of parasites differed between threatened and non-threatened host species. 2. We collated data on 386 species of parasites (including viruses, bacteria, protozoa, helminths and arthropods) reported to infect wild populations of 36 threatened and 81 non-threatened primate species. Analyses controlled for uneven sampling effort and host phylogeny. 3. Results showed that total parasite species richness was lower among threatened primates, supporting the prediction that small, isolated host populations harbour fewer parasite species. This trend was consistent across three major parasite groups found in primates (helminths, protozoa and viruses). Counter to our predictions, patterns of parasite species richness were independent of parasite transmission mode and the degree of host specificity. 4. We also examined the prevalence of selected parasite genera among primate sister-taxa that differed in their ranked threat categories, but found no significant differences in prevalence between threatened and non-threatened hosts. 5. This study is the first to demonstrate differences in parasite richness relative to host threat status. Results indicate that human activities and host characteristics that increase the extinction risk of wild animal species may lead simultaneously to the loss of parasites. Lower average parasite richness in threatened host taxa also points to the need for a better understanding of the cascading effects of host biodiversity loss for affiliated parasite species.
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| 4. |
- Edgell, Amanda B, et al.
(författare)
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Establishing Pathways to Democracy Using Domination Analysis
- 2020
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Ingår i: SSRN Electronic Journal. - Göteborg : Göteborgs universitet. - 1556-5068.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- How does the order in which liberalization unfolds affect the likelihood for a successful democratic transition? Dahl was among the first to argue that the sequence matters for the outcome when it comes to democratization. This paper builds upon his work and empirically analyzes pathways to democracy employing the newly developed method of domination analysis. We are the first to demonstrate three key findings: 1) There is a clear structure in terms of order of how most episodes of liberalization from authoritarian rule develop; 2) Such sequences are different in key respects for failed and successful episodes of liberalization; and 3) Clean election elements - in the capacity of electoral management bodies - stand out as developing earlier in episodes that successfully lead to democracy.
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| 7. |
- Gustafsson, Anders, et al.
(författare)
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Human size evolution : no allometric relationship between male and female stature
- 2004
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Ingår i: Journal of Human Evolution. - : Elsevier BV. - 0047-2484 .- 1095-8606. ; 47:4, s. 253-266
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Tidskriftsartikel (refereegranskat)abstract
- In many animal groups, sexual size dimorphism tends to be more pronounced in species with large body size. Similarly, in a previous cross-cultural analysis, male and female stature in humans were shown to be positively allometrically related, indicating a similar relationship where populations with larger stature were more dimorphic. In this study, we re-examine the hypothesis of an allometric relationship between the sexes using phylogenetic methodology. First, however, we tested whether there exist phylogenetic signals in male and female stature. Data on mean stature from 124 human populations was gathered from the literature. A phylogenetic test showed that male and female stature were significantly associated with phylogeny. These results indicate that comparative methods that to some degree incorporate genetic relatedness between populations are crucial when analyzing human size evolution in a cross-cultural context. Further, neither non-phylogenetic nor phylogenetic analyses revealed any allometric relationship between male and female stature. Thus, we found no support for the idea that sexual dimorphism increases with increasing stature in humans
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| 9. |
- Gustafsson, Anders, et al.
(författare)
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Stature and sexual stature dimorphism in Sweden, from the 10th to the end of the 20th century
- 2007
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Ingår i: American Journal of Human Biology. - : Wiley. - 1042-0533 .- 1520-6300. ; 19:6, s. 861-870
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Tidskriftsartikel (refereegranskat)abstract
- Mean stature in a population has been observed to vary with living conditions. If, and how, this affects sexual dimorphism in stature is not fully understood. We analyzed stature data from Swedish populations from the 10th to the end of the 20th century to investigate if male stature is more plastic than female stature in response to environmental changes. Further, we examined if there, as a consequence of this, exists an allometric relationship between male and female stature that is not caused by genetic factors, coupling greater stature with greater dimorphism. We found no significant change in stature from the 10th century to the 17th century, but a clear increase in both male and female stature during the 20th century, most likely because of improved living conditions. Regression analyses revealed no consistent change in sexual stature dimorphism over time for any of the time periods, including the 20th century. Further, we found no significant allometric relationship between male and female stature, and could consequently not identify any significant relationship between stature and stature dimorphism. Thus, contrary to previous suggestions, the regressions did not provide support for the assertion that male stature is more sensitive to environmental changes than female stature, nor that stature dimorphism increases with increasing stature. Am. J. Hum. Biol. 19:861–870, 2007.
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| 10. |
- Isaksson, Sven, et al.
(författare)
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A Novel Method to Analyze Social Transmission in Chronologically Sequenced Assemblages, Implemented on Cultural Inheritance of the Art of Cooking
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Here we present an analytical technique for the measurement and evaluation of changes in chronologically sequenced assemblages. To illustrate the method, we studied the cultural evolution of European cooking as revealed in seven cook books dispersed over the past 800 years. We investigated if changes in the set of commonly used ingredients were mainly gradual or subject to fashion fluctuations. Applying our method to the data from the cook books revealed that overall, there is a clear continuity in cooking over the ages - cooking is knowledge that is passed down through generations, not something (re-) invented by each generation on its own. Looking at three main categories of ingredients separately (spices, animal products and vegetables), however, disclosed that all ingredients do not change according to the same pattern. While choice of animal products was very conservative, changing completely sequentially, changes in the choices of spices, but also of vegetables, were more unbounded. We hypothesize that this may be due a combination of fashion fluctuations and changes in availability due to contact with the Americas during our study time period. The presented method is also usable on other assemblage type data, and can thus be of utility for analyzing sequential archaeological data from the same area or other similarly organized material.
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