selection


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Related to selection: Selection sort

se·lec·tion

(sĕ-lek'shŭn),
The combined effect of the causes and consequences of genetic factors that determine the average number of progeny of a species that attain sexual maturity; phenotypes that are lethal early in life (for example, Tay-Sachs disease), that cause sterility (for example, Turner syndrome), or that produce sterile progeny are selected against. When selection is used of individual pedigrees, other factors, notably variance of the number of progeny and number that survive to maturity, are important considerations; in large populations, these factors even out and the mean only is of importance.
[L. se-ligo, to separate, select, fr. se, apart, + lego, to pick out]

selection

/se·lec·tion/ (sĕ-lek´shun) the play of forces that determines the relative reproductive performance of the various genotypes in a population.
directional selection  selection favoring individuals at one extreme of the distribution.
disruptive selection , diversifying selection selection favoring the two extremes rather than the intermediate.
natural selection  the survival in nature of those individuals and their progeny best equipped to adapt to environmental conditions.
sexual selection  natural selection in which certain characteristics attract male or female members of a species, thus ensuring survival of those characteristics.
stabilizing selection  selection favoring intermediate phenotypes rather than those at one or both extremes.

selection

(sĭ-lĕk′shən)
n.
Biology A natural or artificial process that involves the survival and reproduction of some kinds of organisms instead of others (because they have traits that are better adapted to the environment or that are preferred by a breeder, for example) and results in changes in the traits of a population or species.

se·lec′tion·al (-shə-nəl) adj.

selection

[silek′shən]
Etymology: L, seligere, to choose
1 the act or product of choosing.
2 the process by which various factors or mechanisms determine and modify the reproductive ability of individuals with specific genotypes within a population, thus influencing evolutionary change. Kinds of selection are artificial selection, natural selection, and sexual selection.

selection

Vox populi The chosing among a number of different options. See Adverse selection, Artificial selection, Group selection, Kin selection, Negative selection, Patient selection, Sex selection.

se·lec·tion

(sĕ-lek'shŭn)
The combined effect of the causes and consequences of genetic factors that determine the average number of progeny of a species that attain sexual maturity.
[L. se-ligo, to separate, select, fr. se, apart, + lego, to pick out]

selection

the differential rate of reproduction of one phenotype in a population as compared to other phenotypes. Hence an organism that produces more offspring which survive to reproduce than another type is at a ‘selective advantage’. The environmental pressures causing selection can be either natural (e.g. competition for food) or artificial (e.g. insecticides, see DDT). See DIRECTIONAL SELECTION, NATURAL SELECTION, STABILIZING SELECTION.

se·lec·tion

(sĕ-lek'shŭn)
The combined effect of the causes and consequences of genetic factors that determine the average number of progeny of a species that attain sexual maturity.
[L. se-ligo, to separate, select, fr. se, apart, + lego, to pick out]

selection,

n 1. the act of choosing between or among a variety of options or alternatives.
2. the process by which various factors or mechanisms determine and modify the reproductive ability of a genotype within a specific population. Also referred to as
natural selection.
selection, shade (tooth color selection),
n the determination of the color (hue, brilliance, saturation, translucency) of the artificial tooth or set of teeth for a given patient.
selection, tooth,
n the selection of a tooth or teeth (shape, size, color) to harmonize with the individual characteristics of a patient.
selection, tooth color,
n See selection, shade.

selection

1. choosing the individual units to be included in a sample. See also random selection.
2. choosing the animals to be retained for breeding purposes; genetic selection.

artificial selection
selection based on human decisions.
selection coefficient
proportionate reduction in the average genetic contribution made by a specific genotype, relative to the contribution made by another genotype. Denoted by s.
selection criteria
the animal characteristic which is used in a selection program.
selection differential
a measure of the gain achieved by selection; the phenotypic superiority of selected individuals, compared to the population from which they were selected.
selection index
a single overall estimate of the patient's true breeding value obtained from as many sources of information as are available.
individual selection
selection on the results of performance testing of the subject.
selection intensity
the superiority of the individuals selected for breeding, relative to the population from which they were selected.
selection limit
the situation in which the entire population is homozygous for the same set of favorable genes; called also selection plateau.
selection/mutation balance
when the rate of removal of a gene from the population by selection equals the rate at which mutations occur.
selection plateau
see selection limit.
selection program
the method used to select individuals from a population to be used for breeding. Usually includes nomination of the characters to be selected, the optimum size of the population in which the program is to operate, the intensity of selection available, the accuracy of the selection procedures, lengths of the generations in the species, the target rate of response.

Patient discussion about selection

Q. clonex symptoms in Selective Mutism Syndrome children My son is 6.5 years old, with selective mutism syndrome - in a months time he shall be entering first grade. We have, the past 2 years been with therapists specializing in this field. He has improved outside a closed system i.e. within the kindergarten (primarily) we even see some regression. We have been at major dilemmas with giving him medication but due to the critical time - we were recommended to take 0.125 mg of Clonex medication. we are a little worried and would like to understand the possible symptoms

A. As a benzodiazepin, it can cause drowsiness, weakness and other changes in behavior. There may be some other side-effects, that you can read about here (http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682279.html)

More discussions about selection
References in periodicals archive ?
As a result, classic, incremental natural selection cannot possibly generate very fit, complex forms with a high number of interconnections compared to the number of parts.
Another possible role for an Institutes of Excellence program is that it would enable insurers to delegate the difficult issue of patient selection criteria to a limited number of institutions and to minimize patient "shopping.
One of the most highly touted two-way linemen in the country, Fua was an all-state second-team selection after leading the Celts to their second consecutive Div.
The League supports changes in the presidential election system--from the candidate selection process to the general election--to provide voters with sufficient information about candidates and their positions, public policy issues and the selection process itself.
All of Richard Gardner's criteria for selection in 1981 are relevant to a greater or lesser degree today.
Although winter nurseries were utilized where applicable for selfing or recombination to reduce cycle times, all progeny evaluation trials for each selection method were conducted in central and southern Iowa, the intended area of use for this germplasm.
These omissions become especially striking when one turns to Hurmence's selections and counts responses among the twenty-one excerpts: Thirteen informants, perhaps resorting to "jaw sense," state that they had good masters.
Some will respond that natural selection stiff operates through our own actions: "You can't repeal a law of nature.
It provides a basis for course selection in future years.
BMW Premium Selection vehicles can now be ordered through exclusive BMW Premium Selection dealerships at seven locations in the Indian market, Bird Automotive (Gurgaon), Krishna Automobiles (Ludhiana), Infinity Cars (South Mumbai), Bavaria Motors (Pune), Navnit Motors (Bangalore), KUN Exclusive (Chennai) and KUN Exclusive (Hyderabad).
For a digital imagery project, one of the most commonly used selection methods will be the Magnetic Lasso located under the Lasso tool.
Arizonans believe that our merit selection system, adopted in 1974 by the electorate, should serve as a nationwide model.