scholarly journals Directional selection for flowering time leads to adaptive evolution inRaphanus raphanistrum(Wild radish)

2016 ◽  
Vol 9 (4) ◽  
pp. 619-629 ◽  
Author(s):  
Michael B. Ashworth ◽  
Michael J. Walsh ◽  
Ken C. Flower ◽  
Martin M. Vila-Aiub ◽  
Stephen B. Powles
Keyword(s):  
Flowering Time ◽  
Adaptive Evolution ◽  
Directional Selection ◽  
Wild Radish ◽  
Selection For

Effects of disruptive selection for flowering time in Brassica campestris var. brown sarson

Heredity ◽  
1972 ◽  
Vol 28 (3) ◽  
pp. 287-295 ◽  
Author(s):  
B R Murty ◽  
V Arunachalam ◽  
P C Doloi ◽  
J Ram
Keyword(s):  
Flowering Time ◽  
Brassica Campestris ◽  
Disruptive Selection ◽  
Selection For ◽  
Brown Sarson

scholarly journals Selection for recombination in a polygenic model – the mechanism

1988 ◽  
Vol 51 (1) ◽  
pp. 59-63 ◽  
Author(s):  
J. Maynard Smith
Keyword(s):  
Linkage Disequilibrium ◽  
Recombination Rate ◽  
Phenotypic Variability ◽  
Directional Selection ◽  
Polygenic Model ◽  
Infinite Population ◽  
Selection For ◽  
Repulsion Linkage

SummaryA polygenic model has been simulated in order to reveal the process whereby selection in an infinite population can lead to an increase in the frequency of alleles causing higher rates of recombination (CH alleles). Directional selection generates repulsion linkage disequilibrium (+ − + −), which is less strong in CH gametes (gametes carrying CH alleles). In consequence, CH gametes contribute greater phenotypic variability, and therefore respond more to directional selection: that is, they accumulate more selectively favoured alleles. CH alleles then increase in frequency by hitch-hiking. In contrast, normalizing selection, or frequent changes in the direction of selection, favour alleles for a low recombination rate.

scholarly journals Dearth of polymorphism associated with a sustained response to selection for flowering time in maize

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Eleonore Durand ◽  
Maud I Tenaillon ◽  
Xavier Raffoux ◽  
Stéphanie Thépot ◽  
Matthieu Falque ◽  
...  
Keyword(s):  
Flowering Time ◽  
Sustained Response ◽  
Response To Selection ◽  
Selection For

scholarly journals Phenotypic plasticity and adaptive evolution contribute to advancing flowering phenology in response to climate change

2012 ◽  
Vol 279 (1743) ◽  
pp. 3843-3852 ◽  
Author(s):  
Jill T. Anderson ◽  
David W. Inouye ◽  
Amy M. McKinney ◽  
Robert I. Colautti ◽  
Tom Mitchell-Olds
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Adaptive Evolution ◽  
Field Experiments ◽  
Flowering Phenology ◽  
Directional Selection ◽  
Major Life ◽  
Quantitative Genetic ◽  
Evolutionary Response

Anthropogenic climate change has already altered the timing of major life-history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie rapid phenological shifts in response to climate change, but their relative contributions are poorly understood. Here, we combine a continuous 38 year field survey with quantitative genetic field experiments to assess adaptation in the context of climate change. We focused on Boechera stricta (Brassicaeae), a mustard native to the US Rocky Mountains. Flowering phenology advanced significantly from 1973 to 2011, and was strongly associated with warmer temperatures and earlier snowmelt dates. Strong directional selection favoured earlier flowering in contemporary environments (2010–2011). Climate change could drive this directional selection, and promote even earlier flowering as temperatures continue to increase. Our quantitative genetic analyses predict a response to selection of 0.2 to 0.5 days acceleration in flowering per generation, which could account for more than 20 per cent of the phenological change observed in the long-term dataset. However, the strength of directional selection and the predicted evolutionary response are likely much greater now than even 30 years ago because of rapidly changing climatic conditions. We predict that adaptation will likely be necessary for long-term in situ persistence in the context of climate change.

scholarly journals New insights on equid locomotor evolution from the lumbar region of fossil horses

2016 ◽  
Vol 283 (1829) ◽  
pp. 20152947 ◽  
Author(s):  
Katrina Elizabeth Jones
Keyword(s):  
Body Size ◽  
Adaptive Evolution ◽  
Axial Skeleton ◽  
Lumbar Region ◽  
Scaling Effects ◽  
Classic Case ◽  
Strong Selection ◽  
Selection For ◽  
Joint Shape

The specialization of equid limbs for cursoriality is a classic case of adaptive evolution, but the role of the axial skeleton in this famous transition is not well understood. Extant horses are extremely fast and efficient runners, which use a stiff-backed gallop with reduced bending of the lumbar region relative to other mammals. This study tests the hypothesis that stiff-backed running in horses evolved in response to evolutionary increases in body size by examining lumbar joint shape from a broad sample of fossil equids in a phylogenetic context. Lumbar joint shape scaling suggests that stability of the lumbar region does correlate with size through equid evolution. However, scaling effects were dampened in the posterior lumbar region, near the sacrum, which suggests strong selection for sagittal mobility in association with locomotor–respiratory coupling near the lumbosacral joint. I hypothesize that small-bodied fossil horses may have used a speed-dependent running gait, switching between stiff-backed and flex-backed galloping as speed increased.

scholarly journals Increased recombination frequencies resulting from directional selection for geotaxis in Drosophila

Heredity ◽  
1994 ◽  
Vol 72 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Abraham B Korol ◽  
Konstantin G Iliadi
Keyword(s):  
Directional Selection ◽  
Selection For
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