genetic drift


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Related to genetic drift: gene flow

ge·net·ic drift

a change in the frequencies of genetic traits or allele frequencies over generations.

genetic drift

n.
Variation in gene frequencies in a population due to chance rather than natural selection, mutation, or immigration.

genetic drift

a gradual change in the allelic frequencies within a population as a result of chance. The smaller a population is, the greater is the tendency for variation within each generation so that eventually small, isolated, inbreeding groups become genetically quite different from their ancestors. Also called random genetic drift.

genetic drift

see RANDOM GENETIC DRIFT.

genetic

1. pertaining to reproduction or to birth or origin.
2. inherited.

genetic abnormality
inherited defect, which may or may not be congenital.
genetic analysis
analysis of breeding and pedigree records to establish degrees of relationship between single animals and groups of animals. Segregation analysis with full-sibling families is an obvious technique.
genetic code
the manner in which the arrangement of nucleotides in the polynucleotide chain of a chromosome governs the transmission of genetic information to proteins, i.e. determines the sequence of amino acids in the polypeptide chain making up each protein synthesized by the cell. Genetic information is coded in DNA by means of four bases (two purines: adenine and guanine; and two pyrimidines: thymine and cystosine). Each adjacent sequence of three bases (a codon) determines which of the 20 amino acids will be inserted into the nascent polypeptide.
genetic complementation
genetic control of inherited disease
consists of preventing carrier animals from contributing their genes to succeeding generations of the population of which they are members.
genetic correlation
a change in an unselected character resulting from selection of another character during a breeding program.
genetic defects
defects of function or structure passed on from parents to offspring. Inherited defects.
genetic determination
see broad-sense heritability.
genetic disease resistance
inherited resistance to diseases caused by non-hereditary risk factors.
genetic dominance
see dominance (2).
genetic drift
see antigenic drift.
genetic engineering
the manipulation of genes by recombinant DNA technologies to produce chromosomal combinations that are unlikely to occur by natural means, for example the introduction of genes for insulin into a yeast cell which then produces insulin which can be purified and used as a therapeutic substance. See also recombinant DNA technology.
genetic etiology
disease caused by inheritance of specific disease without the intervention of other risk factors; established by strongly positive relationship in terms of genes held in common between the affected patient and other affected individuals.
genetic evaluation
assessment, for predictive purposes, of productive improvement or conformational characteristics, of the gain to be derived by the use of the animal in question in a breeding program.
genetic expressivity
genetic heterogeneity
demonstrated by the way in which more than one disease with identical clinical signs can be inherited.
genetic immunization
use of a cloned genetically engineered gene with an encoded antigen to immunize the host against that antigen. See also DNA vaccine.
genetic map
the linear arrangement of genes along a chromosome. Called also linkage map.
genetic merit
inherited productivity or performance qualities.
mobile genetic elements
see transposable genetic elements (below).
genetic penetrance
genetic production potential
inherited productivity but still influenced by environmental risk factors.
genetic resistance
genetically determined resistance to specified infectious agents.
genetic selection
selection of animals as breeding stock on the basis of known inherited characteristics.
transposable genetic elements
pieces of DNA varying in length from a few hundred to tens of thousands of base pairs found in both prokaryotic and eukaryotic cells that move from place to place in the chromosomes of a single cell; some are viruses. Called also mobile genetic elements or transposons.
genetic variance
that portion of the phenotypic variance of a trait in a population which can be attributed to genetic difference amongst individuals.
References in periodicals archive ?
As such reduced heterozygosity due to genetic drift and/or inbreeding is a significant concern.
Estimation of parameters of inbreeding and genetic drift in populations with overlapping generations.
e] ratio can be used to quantify of only genetic drift influence on amount of GD, excluding the effect of founder contribution.
This coincidence supports the hypothesis that the morpho-anatomical differences observed between populations are a consequence of local differentiation by genetic drift rather than an ability of plants in this species to express different phenotypes with the same genotype (phenotypic plasticity) or local selection.
Thus, these differences presumably indicate the strong effect of founding combined with genetic drift associated with isolation from neighboring populations.
After sifting through a vast cache of DNA broadly representative of global diversity, Lahn's team located an allele for each gene that occurred so frequently that it simply had to have been adaptive rather than merely the stray product of genetic drift or group migration.
Partial sequencing of the NA and hemagglutinin (HA) genes was performed to confirm the NA H274Y resistance mutation and to determine genetic drift in HA from the A/Brisbane/59/2007 virus recommended for the Northern Hemisphere 2007-08 vaccine.
The researchers concluded that random genetic change, or genetic drift, most likely accounts for the cranial differences.
Probabilities of gene origin suggest that genetic variation has decreased in this population due to a bottleneck effect and genetic drift, without increasing inbreeding.
The results underscore the importance of human transport as a dispersal mechanism and the importance of genetic drift and founder effects in determining population genetic structure.
genetic drift and inbreeding), and environmental catastrophes (e.