| 1. |
- Adolfsson, S, et al.
(författare)
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The spread of apomixis and its effect on resident genetic variation
- 2007
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Ingår i: Journal of evolutionary biology. - : Wiley. - 1420-9101 .- 1010-061X. ; 20:5, s. 1933-1940
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Tidskriftsartikel (refereegranskat)abstract
- In a simulation model we investigated how much of the initial genetic variation that is retained in a population after a dominant mutation has brought apomixis to fixation in it. A marker allele associated with the apomixis mutation is generally retained after the fixation of apomixis, particularly if the two alleles are closely linked. The spread of asexuality, however, normally leads to almost no loss of genetic variation, neither with respect to cytotypes nor with respect to genotypes. This holds for large populations and apomixis mutants with strong pollen production. In smaller populations, and with apomicts with reduced pollen production, the outcome is more variable, ranging from no genetic variation retained to only weakly reduced variability compared with the initial state. These results help explain the high genetic variability in many apomicts. They also imply that natural selection will have many genotypes to act on even after the spread of apomixis.
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| 2. |
- Bengtsson, Bengt Olle, et al.
(författare)
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Asex and Evolution: A Very Large-Scale Overview
- 2009
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Ingår i: Lost Sex. - Dordrecht : Springer Netherlands. - 9789048127696 ; , s. 1-19
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Asexuals come in all sorts. In this personal overview, I identify asexual organisms with eukaryotes that do not regularly go through the meiotic cycle. Such organisms may be asexual in many different ways and of many different reasons. The spread of asexuality is therefore always a unique process, and any notion of a general evolutionary advantage for asexuality is at best misleading. In discussions on the evolution of asexuality, ideas about genetic conflicts are often more helpful than notions about “costs”. Many asexuals are associated with different fitness problems, and most of them are not particularly good at being asexual either. Their absence of long-term evolutionary success follows from their lack of recombination, leading to complex effects involving drift and selection that we are just beginning to understand. The interest in asexual organisms comes not from what they say about sex, but from what they say about living as a eukaryote.
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| 3. |
- Bengtsson, Bengt Olle
(författare)
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Den svårfångade genen
- 2008
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Ingår i: Dagens Nyheter. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 4. |
- Bengtsson, Bengt Olle, et al.
(författare)
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Direct and indirect selection in moth pheromone evolution: population genetical simulations of asymmetric sexual interactions
- 2007
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066. ; 90:1, s. 117-123
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Tidskriftsartikel (refereegranskat)abstract
- Female moths generally use pheromones to attract males. Normally, all females in a population produce a specific chemical blend with only a limited variance, and the local males are highly attracted to this blend. To better understand the direct and indirect selective forces acting on this communication system, where, unusually, it is the reproductively limited sex that signals for matings, a population genetical model has been constructed and numerically analysed. Basic to the model is the assumption that the pheromone attraction system functions asymmetrically, leading to strong sexual selection between males but no direct sexual selection between females. Evolutionary simulations using the model show that sexual selection in males causes an indirect stabilizing selection on the pheromone blends produced by females. Thus, a more narrow range of pheromone variation is selected for, even in the absence of female sexual selection. The strength of the selection is analysed, and it is suggested that this indirect stabilizing selection becomes particularly important in situations where geographically adjacent populations have evolved different pheromone blends.
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| 5. |
- Bengtsson, Bengt Olle
(författare)
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Eftertankens kultur
- 2006
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Ingår i: Det eviga som traditionsbrott. - 9789163184819 ; , s. 23-25
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Bokkapitel (populärvet., debatt m.m.)
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| 6. |
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| 7. |
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| 8. |
- Bengtsson, Bengt Olle
(författare)
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"Munkavle på forskare?"
- 2006
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Ingår i: Sydsvenska dagbladet. - 1104-0068.
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 9. |
- Bengtsson, Bengt Olle, et al.
(författare)
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Rävens politik
- 2008
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Ingår i: Universitetets frihet.. - 9789163324109 ; , s. 81-88
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Bokkapitel (populärvet., debatt m.m.)abstract
- Abstract is not available
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| 10. |
- Bengtsson, Bengt Olle, et al.
(författare)
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The effective size of bryophyte populations.
- 2009
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Ingår i: Journal of Theoretical Biology. - : Elsevier BV. - 1095-8541 .- 0022-5193. ; 258:Available online 8 January 2009, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- Bryophytes with their dominant haploid stage conform poorly to the life cycles generally treated in population genetical models. Here we make a detailed analysis of what effective sizes bryophyte model populations have as a function of their breeding system. It is found that the effective size is rarely much smaller than the scored number of haploid gametophytic individuals, even when the limited number of diploids (sporophytes) formed is taken into account. The most severe decrease in effective size occurs when unisexual gametophytic females produce only a small number of fertile diploid sporophytes in male biased populations; this effect is due to the restricted sampling of male gametophytic individuals that then occurs. It is shown that the harmonic mean of diploid sporophytes formed per haploid gametophytic individuals is the relevant measure in these calculations and not the standard (and generally larger) arithmetic mean.
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