British scientist Francis Crick, left, and his American colleague James Watson revolutionized the field of genetics when they discovered the double-helix structure of deoxyribonucleic acid (DNA), the genetic blueprint for all living organisms.
Illustration by Ned M. Seidler, National Geographic
  • On April 25, 1953, molecular biologists James Watson and Francis Crick published a paper describing the double-helix structure of deoxyribonucleic acid (DNA). DNA is a molecule shared by all living organisms. Each molecule of DNA is encoded with information about the individual organism.
    Watson and Crick’s discovery of DNA’s structure answered a crucial scientific question—how do living things reproduce themselves? Watson and Crick described how the twisted-ladder shape of DNA “unzipped” and replicated itself. As the enthusiastic Watson proclaimed to his friends “We have discovered the secret of life!”
    The double helix was perhaps not the secret of life, but it did revolutionize the field of genetics. The Human Genome Project, for example, is an enormous, international effort to identify and map all the genes in the human genome. National Geographic’s Genographic Project uses genetics to help trace the migratory history of the human species.
    Watson wrote a nicely readable book about their discovery, The Double Helix. He, Crick, and their colleague Maurice Wilkins were awarded the Nobel Prize in Medicine in 1962. Today, several scientific organizations celebrate April 25 as “DNA Day.”
  • Term Part of Speech Definition Encyclopedic Entry
    colleague Noun

    a coworker or partner.

    crucial Adjective

    very important.

    DNA Noun

    (deoxyribonucleic acid) molecule in every living organism that contains specific genetic information on that organism.

    enormous Adjective

    very large.

    enthusiastic Adjective


    gene Noun

    part of DNA that is the basic unit of heredity.

    genetics Noun

    the study of heredity, or how characteristics are passed down from one generation to the next.

    Genographic Project Noun

    National Geographic project that uses genealogy to trace the migratory history of the human species.

    genome Noun

    set of genes, or chromosomes, that hold all the inherited characteristics of an organism.

    helix Noun

    spiral shape.

    identify Verb

    to recognize or establish the identity of something.

    migratory Adjective

    organisms that travel from one place to another at predictable times of the year.

    molecular biologist Noun scientist who studies the structure and activity of molecules essential to life.
    molecule Noun

    smallest physical unit of a substance, consisting of two or more atoms linked together.

    proclaim Verb

    to announce publicly.

    replicate Verb

    to duplicate or reproduce.

    revolutionize Verb

    to completely change a process or way of doing something.