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 ?
Pairwise differentiation was significant between many hatchery-by-hatchery, and some hatchery-by-wild comparisons, likely reflecting genetic drift associated with broodstock selection and breeding practices.
The continuous increase in the total loss of GD due to the unequal founder contribution and random genetic drift over the last decade has been observed only in CLWs and PN breeds.
For example, if population sizes have been historically small, random genetic drift since the post-glacial colonization events would have lead to low levels of intrapopulation genetic diversity even if the populations originated from multiple sources.
There are argument between scientist that whether artificial propagation of Caspian Sea brown trout conserve gene bank of this species and prevent genetic drift or not.
Among the other points of contention are the mechanisms (theories) by which evolution occurs: random genetic variation, natural selection, and genetic drift.
61) The most common areas of environmental concern include threats to biodiversity, decline in yields, threats to animal species (especially insects), genetic drift, and the possibility of crossbreeding with hardy invasive species to produce "superweeds.
Within-population genetic variation is expected to be small compared to between-population variation in species with small ranges and fragmented distributions, mainly due to genetic drift or founder effects and small effective population size (Peterson et al.
Topics include general background, measures of genetic variation, genetic drift and effective population size, mutation, neutral theory and coalescence, and additional relevant material.
The dictates of evolutionary biology as is evidenced by genetic drift, assorted mating, natural selection, etc.
But until very recently, both the popular and scientific assumptions had been that if humans were still evolving at all, it was through the very slow and completely random process of genetic drift.
One of the primary concerns of conservation biology is the loss of genetic diversity through genetic drift in small populations.
The researchers concluded that random genetic change, or genetic drift, most likely accounts for the cranial differences.