Skip to main content
Biology LibreTexts

5.S: Pedigrees and Populations (Summary)

  1. Last updated
  2. Save as PDF
  • Page ID
    27261

    • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)

    • Pedigree analysis can be used to determine the mode of inheritance of specific traits such as diseases. Loci can be X- or Y-linked or autosomal in location and alleles either dominant or recessive with respect to wild type.
    • If the mode of inheritance is known, a pedigree can be used to calculate the probability of inheritance of a particular genotype by an individual.
    • The frequencies of all alleles and genotypes remain unchanged through successive generations of a population in Hardy-Weinberg equilibrium.
    • Populations in true Hardy-Weinberg equilibrium have random mating, and no genetic drift, no migration, no mutation, and no selection with respect to the gene of interest.
    • The Hardy-Weinberg formula can be used to estimate allele and genotype frequencies given only limited information about a population.

    Key Terms

    Pedigree charts

    mode of inheritance

    genetic counseling

    incomplete penetrance

    variable expressivity

    proband

    affected

    carrier

    autosomal dominant

    autosomal recessive

    X-linked dominant

    X-linked recessive

    Y-linked inheritance

    Y-linked

    mitochondrial inheritance (mtDNA)

    sporadic

    product rule

    sum rule

    population

    p+q=1

    Hardy-Weinberg formula

    p2 + 2pq + q2=1

    Hardy-Weinberg equilibrium

    assortative mating

    random mating

    migration

    genetic drift

    5.S: Pedigrees and Populations (Summary) is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Todd Nickle and Isabelle Barrette-Ng via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.