Quantitative Genetics of Shell Form of an Intertidal Snail: Constraints on Short-Term Response to Selection

Evolution ◽  
1993 ◽  
Vol 47 (2) ◽  
pp. 576 ◽  
Author(s):  
Elizabeth G. Boulding ◽  
Toby K. Hay
Keyword(s):  
Quantitative Genetics ◽  
Response To Selection ◽  
Short Term ◽  
Shell Form ◽  
Intertidal Snail ◽  
Term Response

scholarly journals Response to selection for increased pupa weight in Tribolium castaneum as related to population structure

1977 ◽  
Vol 30 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Alan J. Katz ◽  
Franklin D. Enfield
Keyword(s):  
Random Mating ◽  
Selection Response ◽  
Response To Selection ◽  
Short Term ◽  
Selection Systems ◽  
Line Selection ◽  
Selection For ◽  
Seven Generations ◽  
Generation Period ◽  
Term Response

SUMMARYThe effectiveness of selection for increased pupa weight in Tribolium was compared for three different selection systems. In all three systems the same number of breeding individuals was used each generation. Population L was a large random mating population with 24 males and 48 females selected each generation. The C4 and C8 populations were each divided into 6 subpopulations (lines) consisting of 4 males and 8 fem ales. Each of the three populations was replicated. In C4, selection for pupa weight was within lines for three generations, followed by a generation of among-line selection when the best two out of six lines were selected. These lines were then crossed to produce 6 new subpopulations, and the cycle was repeated. The C8 population was handled in exactly the same manner except that seven generations of selection within lines were practised before each generation of among-line selection. Selection response for the 42-generation period was significantly greater in the L population than in either subdivided population. No consistent differences among the selection systems were apparent when evaluating short-term response for the first 12 generations of the experiment. The results were interpreted as indicating that the influence of multiple-peak epistasis was not of major importance for this trait in determining ultimate response to selection when starting from a base population of previously unselected lines and utilizing a within- and among-line selection regime.

scholarly journals RECOMBINATION AND RESPONSE TO SELECTION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1977 ◽  
Vol 85 (1) ◽  
pp. 125-140
Author(s):  
Vinton Thompson
Keyword(s):  
Drosophila Melanogaster ◽  
Selection Response ◽  
Response To Selection ◽  
Short Term ◽  
Chromosome Recombination ◽  
Suppressed Recombination ◽  
Selection For ◽  
Balancer Chromosomes ◽  
Term Response ◽  
Rate Of Response

ABSTRACT Most biologists believe that recombination speeds response to selection for traits determined by polygenic loci. To test this hypothesis, sixteen Drosophila melanogaster populations were selected for positive phototaxis for twenty-one generations. In some populations, balancer chromosomes were used to suppress autosomal recombination, and in others the autosomes were free to recombine. Suppression of recombination had no effect on mean rate of response to selection, though it may have increased variability in the rate of response among replicate lines. Suppressed recombination lines did not shift selection response to the freely recombining × chromosomes, despite fairly large increases in × chromosome recombination. The results suggest that in populations of moderate size, sex does not accelerate short term response to selection.

scholarly journals The effects of population size and selection intensity in selection for a quantitative character in Drosophila: I. Short-term response to selection

1968 ◽  
Vol 12 (3) ◽  
pp. 237-248 ◽  
Author(s):  
R. Frankham ◽  
L. P. Jones ◽  
J. S. F. Barker
Keyword(s):  
Quantitative Character ◽  
Selection Intensity ◽  
Realized Heritability ◽  
Response To Selection ◽  
Short Term ◽  
Population Sizes ◽  
Selection For ◽  
Selection Intensities ◽  
Number Of Individuals ◽  
Term Response

1. The response to selection for increased number of bristles on one abdominal segment was studied over 12 generations using a factorial design of three population sizes (10, 20 and 40 pairs of parents) and five selection intensities (10, 20, 40, 80% and controls).2. The responses on the average agreed well with those expected from the estimated base population heritability, but individual replicates diverged considerably.3. Larger populations tended to give greater response to selection, due mainly to larger realized heritabilities.4. There was no consistent effect of selection intensity on realized heritability.5. For populations with the same number of individuals scored, less intense selection gave greater realized heritabilities.

Unfolding the case of returnees: How the European Union and its member States are addressing the return of foreign fighters and their families

2021 ◽  
pp. 1-23
Author(s):  
Carlota Rigotti ◽  
Júlia Zomignani Barboza
Keyword(s):  
European Union ◽  
Perceived Threat ◽  
The European Union ◽  
Security Threat ◽  
Short Term ◽  
Member States ◽  
Foreign Fighters ◽  
Term Response

Abstract The return of foreign fighters and their families to the European Union has mostly been considered a security threat by member States, which consequently adopt repressive measures aimed at providing an immediate, short-term response to this perceived threat. In addition to this strong-arm approach, reintegration strategies have also been used to prevent returnees from falling back into terrorism and to break down barriers of hostility between citizens in the long term. Amidst these different strategies, this paper seeks to identify which methods are most desirable for handling returnees.

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