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  2. Allele - Wikipedia

    en.wikipedia.org/wiki/Allele

    Allele. An allele[1], or allelomorph, is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. [2] Alleles can differ at a single position through single nucleotide polymorphisms (SNP), [3] but they can also have insertions and deletions of up to several thousand base pairs. [4]

  3. Population structure (genetics) - Wikipedia

    en.wikipedia.org/wiki/Population_structure...

    Population structure (genetics) Population structure (also called genetic structure and population stratification) is the presence of a systematic difference in allele frequencies between subpopulations. In a randomly mating (or panmictic) population, allele frequencies are expected to be roughly similar between groups.

  4. Gene - Wikipedia

    en.wikipedia.org/wiki/Gene

    When multiple different alleles for a gene are present in a species's population it is called polymorphic. Most different alleles are functionally equivalent, however some alleles can give rise to different phenotypic traits. A gene's most common allele is called the wild type, and rare alleles are called mutants.

  5. Human genetic variation - Wikipedia

    en.wikipedia.org/wiki/Human_genetic_variation

    Human genetic variation is the genetic differences in and among populations. There may be multiple variants of any given gene in the human population (alleles), a situation called polymorphism. No two humans are genetically identical. Even monozygotic twins (who develop from one zygote) have infrequent genetic differences due to mutations ...

  6. Gene polymorphism - Wikipedia

    en.wikipedia.org/wiki/Gene_polymorphism

    Gene polymorphism. Genes which control hair colour are polymorphic. A gene is said to be polymorphic if more than one allele occupies that gene's locus within a population. [1] In addition to having more than one allele at a specific locus, each allele must also occur in the population at a rate of at least 1% to generally be considered ...

  7. Population genetics - Wikipedia

    en.wikipedia.org/wiki/Population_genetics

    ISOGG. v. t. e. Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure. [1]

  8. Major histocompatibility complex - Wikipedia

    en.wikipedia.org/wiki/Major_histocompatibility...

    The most diverse loci, namely HLA-A, HLA-B, and HLA-C, have roughly 6000, 7200, and 5800 known alleles, respectively. [39] Many HLA alleles are ancient, sometimes of closer homology to a chimpanzee MHC alleles than to some other human alleles of the same gene. MHC allelic diversity has challenged evolutionary biologists for explanation.

  9. List of polymorphisms - Wikipedia

    en.wikipedia.org/wiki/List_of_polymorphisms

    Here we see a system where there are more than two morphs: the phenotypes A, B, AB and O are present in all human populations, but vary in proportion in different parts of the world. The phenotypes are controlled by multiple alleles at one locus. These polymorphisms are seemingly never eliminated by natural selection; the reason came from a ...