timeline in genetics

By jane benedetto
  • 1943 BCE

    Discovery: DNA Has a Regular Periodic Structure

    William Astbury, a British scientist, obtains the first X-ray
    diffraction pattern of DNA, which reveals that DNA must
    have a regular periodic structure. He suggests that nucleotide
    bases are stacked on top of each other.
  • 1941 BCE

    Discovery: One Gene, One Enzyme Hypothesis

    George Beadle and Edward Tatum’s experiments on the red
    bread mold, Neurospora crassa, show that genes act by
    regulating distinct chemical events. They propose that each
    gene directs the formation of one enzyme
  • 1911 BCE

    Discovery: Chromosomes Carry Genes

    Discovery: Chromosomes Carry Genes
    Thomas Hunt Morgan and his students study fruit fly
    chromosomes. They show that chromosomes carry genes, and
    also discover genetic linkage.
  • 1909 BCE

    Discovery: The Word Gene is Coined

    Discovery: The Word Gene is Coined
    Wilhelm Johannsen coins the word “gene” to describe the
    Mendelian unit of heredity. He also uses the terms genotype
    and phenotype to differentiate between the genetic traits of an
    individual and its outward appearance.
  • 1902 BCE

    Discovery: Orderly Inheritance of Disease

    A British physician, Archibald Garrod, observes that the
    disease alkaptonuria is inherited according to Mendelian rules.
    This disease involves a recessive mutation, and was among the
    first conditions ascribed to a genetic cause.
  • 1900 BCE

    Discovery: Rediscovery of Mendel’s work

    Botanists DeVries, Correns, and von Tschermak independently
    rediscover Mendel’s work while doing their own work on the
    laws of inheritance. The increased understanding of cells and
    chromosomes at this time allowed the placement of Mendel’s
    abstract ideas into a physical context.
  • 1879 BCE

    Discovery: Mitosis Described

    Walter Flemming describes chromosome behavior during
    animal cell division. He stains chromosomes to observe them
    clearly and describes the whole process of mitosis in 1882.
  • 1869 BCE

    Discovery: DNA Isolated

    Discovery: DNA Isolated
    Frederick Miescher isolates DNA from cells for the first time
    and calls it “nuclein
  • 1865 BCE

    Discovery: Heredity Transmitted in Units

    Discovery: Heredity Transmitted in Units
    Gregor Mendel’s experiments on peas demonstrate that
    heredity is transmitted in discrete units. The understanding
    that genes remain distinct entities even if the characteristics
    of parents appear to blend in their children explains how
    natural selection could work and provides support for
    Darwin’s proposal.
  • 1859 BCE

    Discovery: Natural Selection

    Discovery: Natural Selection
    Charles Darwin wrote “On the Origin of Species by Means of
    Natural Selection, or the Preservation of Favored Races in the
    Struggle for Life.”