| 1. |
- Moore, F. R., et al.
(författare)
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Cross-cultural variation in women's preferences for cues to sex- and stress-hormones in the male face
- 2013
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Ingår i: Biology letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Women in the UK prefer the faces of men with low levels of the stress hormone cortisol, and the relationship is moderated by the sex hormone testosterone. In a Latvian sample, however, women's preferences were not affected by cortisol, and the interaction with testosterone differed from that of the UK. To further explore cross-cultural variation in preferences for facial cues to sex- and stress-hormones, we tested the preferences of women from 13 countries for facial composites constructed to differ in combinations of the hormones. We found significant relationships between a measure of societal development (the United Nations human development index 2011) and preferences for cues to testosterone in the face, and the interaction between preferences for cues to testosterone and cortisol. We also found a significant relationship between preferences for cues to testosterone and a societal-level measure of parasite stress. We conclude that societal-level ecological factors influence the relative value of traits revealed by combinations of sex- and stress-hormones.
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| 2. |
- Laaksonen, T., et al.
(författare)
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Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers
- 2015
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 28:4, s. 779-790
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Tidskriftsartikel (refereegranskat)abstract
- Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation (P-ST) was higher than that in neutral genetic markers (F-ST), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns.
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| 3. |
- Lehtonen, PK, et al.
(författare)
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Candidate genes for colour and vision exhibit signals of selection across the pied flycatcher (Ficedula hypoleuca) breeding range
- 2012
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Ingår i: Heredity. - : Springer Science and Business Media LLC. - 1365-2540 .- 0018-067X. ; 108:4, s. 431-440
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Tidskriftsartikel (refereegranskat)abstract
- The role of natural selection in shaping adaptive trait differentiation in natural populations has long been recognized. Determining its molecular basis, however, remains a challenge. Here, we search for signals of selection in candidate genes for colour and its perception in a passerine bird. Pied flycatcher plumage varies geographically in both its structural and pigment-based properties. Both characteristics appear to be shaped by selection. A single-locus outlier test revealed 2 of 14 loci to show significantly elevated signals of divergence. The first of these, the follistatin gene, is expressed in the developing feather bud and is found in pathways with genes that determine the structure of feathers and may thus be important in generating variation in structural colouration. The second is a gene potentially underlying the ability to detect this variation: SWS1 opsin. These two loci were most differentiated in two Spanish pied flycatcher populations, which are also among the populations that have the highest UV reflectance. The follistatin and SWS1 opsin genes thus provide strong candidates for future investigations on the molecular basis of adaptively significant traits and their co-evolution.
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