a mechanism of evolution that occurs when a small group of individuals leaves a population and establishes a new one in a geographically isolated region.

changes in allele frequencies within a population due to random processes (i.e., not selection); most prevalent in small populations.

random changes in the frequency of alleles in a population. In small populations, it can lead to the elimination of a particular allele by chance alone. It is thought to be one cause of speciation when a group of organisms is separated from its parent population

The accumulation of point mutations which subtly alter the antigenic structure of the virus.

Changes in gene/allele frequencies in a POPULATION over many GENERATION resulting from chance rather than SELECTION. Occurs most rapidly in small populations. Can lead to some ALLELE becoming `extinct', thus reducing the genetic variability in the population.

A gradual (or sometimes abrupt) change in the germplasm balance of a cross-pollinated cultivar causing a change in its characteristics. Usually applies to grasses or legume cultivars when seed is produced outside their area of adaption. The shift may be caused by selective differences in plant mortality or flowering habit under the different environment.

(see random genetic drift)

Spontaneous variation in the sequence of duplicated genes that developed during evolution; also called sequence drift.

Random fluctuations in the allele and, less commonly, the phenotype frequencies, as genes are transmitted from one generation to the next.

Changes in gene frequencies from generation to generation in a small population as a result of random processes.

Random changes in gene frequency within a population resulting from sampling effects rather than natural selection, and hence of greatest importance in small populations.

Changes in the gene frequencies of a population when the size of sample chosen for rejuvenation is small. Genetic drift leads to a loss of certain genotypes in the population.

Random fluctuations in gene frequency occurring in isolated populations from generation to generation. Genetic drift is the result of chance combinations of different characteristics.

(ge·NET·ic drift). A variation in the gene pool, a change in allele frequency, in a small population due to chance.

The random fluctuation of allele frequencies in a population resulting from the sampling of gametes to produce a finite number of individuals in the next generation.

random changes in the frequencey of alleles in a gene pool, usually of small populations law Possible outcomes are known/able--but the next outcome is predictable

The tendency of specific alleles to vary in frequency from generation to generation. Rare alleles can be lost to a population by this process. Effects are more pronounced in smaller populations.

the change in allele frequencies over time due to chanceand chance alone.

alteration in gene frequencies that usually occurs in a small population and results from chance processes alone, not from natural selection, mutations, or immigration

The occurrence of changes in gene frequency brought about by chance rather than by selection.

Random fluctuations in the frequency of the appearance of a gene in a small, isolated population, presumably owing to chance rather than natural selection.

the cumulative effect of the chance loss of some genes and the disproportionate replication of others over successive generations resulting in the frequency of the alleles altering from one generation to the next in small populations.

Changes in gene frequencies caused by separation of a small group from a larger population. 408

The occurrence of random changes in the gene frequencies of populations.

the amount of random change in gene frequencies. It depends on the -- effective population size.

the change in frequency in which a gene appears in a population, through mutation, regardless of the adaptive value of the mutation.

Changes in allele frequencies that can be ascribed to random effects.

the random fluctuations of gene frequencies due to sampling errors.

Random changes in the frequency of alleles from generation to generation; especially in small populations, can lead to the elimination of a particular allele by chance alone.

the change of gene frequency from one generation to another caused by the cumulative effects of random fluctuations, rather than by natural selection.

Random variation in gene frequency from one generation to another

Refers to the constant tendency of genes to evolve even in the absence of selective forces. Genetic drift is fuelled by spontaneous neutral mutations that disappear or become fixed in a population at random. Inbred lines separated from a common ancestral pair can drift rapidly apart from each other.

the random change in gene frequencies in populations.

change in gene frequencies in a small populations a result of each generation being unrepresentative of its parents.

Changes in allele frequency in small breeding populations due to chance fluctuations.

Random changes in the frequency of two or more alleles or genotypes within a population.

The fact that chance, rather than selection, may affect gene frequencies when a population is very small (usually fewer than fifty individuals). This phenomenon, like that of the founder principle, is due to "sampling error". genotype The genetic constitution of an individual organism.

The process by which gene frequencies are changed.

Changes in the frequencies of alleles in a population that occur by chance, rather than because of natural selection; especially significant for small populations.

In population genetics, genetic drift is the statistical effect that results from the influence that chance has on the success of alleles (variants of a gene). The effect may cause an allele and the biological trait that it confers to become more common or more rare over successive generations. Ultimately, the drift may either remove the allele from the gene pool or remove all other alleles.