gene flow

(noun)

the transfer of alleles or genes from one population to another

Related Terms

Examples of gene flow in the following topics:

  • Gene Flow and Mutation

    • An important evolutionary force is gene flow: the flow of alleles in and out of a population due to the migration of individuals or gametes.
    • Maintained gene flow between two populations can also lead to a combination of the two gene pools, reducing the genetic variation between the two groups.
    • Gene flow strongly acts against speciation, by recombining the gene pools of the groups, and thus, repairing the developing differences in genetic variation that would have led to full speciation and creation of daughter species.
    • Gene flow can occur when an individual travels from one geographic location to another.
    • Explain how gene flow and mutations can influence the allele frequencies of a population

  • Defining Population Evolution

    • Genetic variation in a population is determined by mutations, natural selection, genetic drift, genetic hitchhiking, and gene flow.
    • Because these individuals can share genes and pass on combinations of genes to the next generation, the collection of these genes is called a gene pool.
    • Five forces can cause genetic variation and evolution in a population: mutations, natural selection, genetic drift, genetic hitchhiking, and gene flow.
    • Gene flow is the exchange of genes between populations or between species.If the gene pools between two populations are different, the exchange of genes can introduce variation that is advantageous or disadvantageous to one of the populations.
    • Describe how the forces of genetic drift, genetic hitchhiking, gene flow, and mutation can lead to differences in population variation

  • Nonrandom Mating and Environmental Variance

    • Genes are not the only players involved in determining population variation.
    • If there is gene flow between the populations, the individuals will likely show gradual differences in phenotype along the cline.
    • Restricted gene flow, on the other hand, can lead to abrupt differences, even speciation.
    • Explain how environmental variance and nonrandom mating can change gene frequencies in a population

  • Allopatric Speciation

    • A geographically-continuous population has a gene pool that is relatively homogeneous.
    • Gene flow, the movement of alleles across the range of the species, is relatively free because individuals can move and then mate with individuals in their new location.
    • When populations become geographically discontinuous, that free-flow of alleles is prevented.
    • If two flying insect populations took up residence in separate nearby valleys, chances are individuals from each population would fly back and forth, continuing gene flow.
    • However, if two rodent populations became divided by the formation of a new lake, continued gene flow would be improbable; therefore, speciation would be probably occur.

  • Gene Duplications and Divergence

    • Gene duplication is the process by which a region of DNA coding for a gene is copied.
    • Duplicate genes are often immune to the selective pressure under which genes normally exist.
    • Many retrogenes display changes in gene regulation in comparison to their parental gene sequences, which sometimes results in novel functions.
    • Divergent evolution is usually a result of diffusion of the same species to different and isolated environments, which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection.Divergent evolution can also be applied to molecular biology characteristics.
    • Both orthologous genes (resulting from a speciation event) and paralogous genes (resulting from gene duplication within a population) can be said to display divergent evolution.

  • RNA Splicing

    • Gene expression is the process that transfers genetic information from a gene made of DNA to a functional gene product made of RNA or protein.
    • Genetic Information flows from DNA to RNA by the process of transcription and then from RNA to protein by the process of translation.
    • In eukaryotes, the gene contains extra sequences that do not code for protein.
    • Alternative splicing allows more than one protein to be produced from a gene and is an important regulatory step in determining which functional proteins are produced from gene expression.
    • Alternative splicing is a process that occurs during gene expression and allows for the production of multiple proteins (protein isoforms) from a single gene coding.

  • Replication of Herpes Simplex Virus

    • Herpes replication entails three phases: gene transcription, viral assembly in the nucleus, and budding through the nuclear membrane.
    • Research using flow cytometry on another member of the herpes virus family, Kaposi's sarcoma-associated herpesvirus, indicates the possibility of an additional lytic stage, delayed-late.
    • This enzyme shuts off protein synthesis in the host, degrades host mRNA, helps in viral replication, and regulates gene expression of viral proteins.
    • An enzyme shuts off protein synthesis in the host, degrades host mRNA, helps in viral replication, and regulates gene expression of viral proteins.

  • Northern Blots

    • The Northern blot is a technique used in molecular biology research to study gene expression in a sample, through detection of RNA (or isolated messenger RNA ).
    • With Northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation, morphogenesis, as well as abnormal or diseased conditions.
    • Flow diagram outlining the general procedure for RNA detection by northern blotting.

  • Gene Families

    • Gene families are groups of functionally related genes arising from a duplicated gene.
    • A gene family is a set of several similar genes, formed by duplication of a single original gene, that generally have similar biochemical functions .
    • If the genes of a gene family encode proteins, the term protein family is often used in an analogous manner to gene family.
    • In contrast, gene complexes are simply tightly linked groups of genes, often created via gene duplication (sometimes called segmental duplication if the duplicates remain side-by-side).
    • Unequal crossing over generates gene families.

  • Epistasis

    • The B gene controls black (B_) vs. brown (bb) color, while the E gene controls yellow (ee) color.
    • Genes may also oppose each other with one gene modifying the expression of another.
    • Often the biochemical basis of epistasis is a gene pathway in which the expression of one gene is dependent on the function of a gene that precedes or follows it in the pathway.
    • In this case, the C gene is epistatic to the A gene.
    • Thus, the C gene is epistatic to the A gene.