Timeline

1655 - Robert Hooke (1635-1703) of Britain designed his own microscope and discovered matter made up of what he called cells.

1759 - C.F. Wolff (1733-1794) of Germany proposed a general cell theory.

1838 - Matthias J. Schleiden (1804-1881) of Germany published a cell theory as applied to plants. 1839 - Theodor Schwann (1810-1882) of Germany published cell theory as applied to animals. 1857 - Gregor Johann Mendel (1822-1884), an Austrian monk, began experiments with pea plants. He later became known as the "father of genetics."

1859 - English biologist Charles Darwin (1809-1882) published “On the Origin of Species,” explaining units of heredity and variations in species. 1865 - Mendel announced his theories of heredity, known as Mendel’s Laws.

1869 - Sir Francis Galton (1822-1911) of Britain published his book, Hereditary Genius, claiming that heredity alone is responsible for a person’s character traits.

1882 - German biologist Walther Fleming (1843-1905) used dyes to stain cells; he discovered rods he called “chromosomes.”

1900 - De Vries published a paper that included the laws of inheritance as do two others: German botanist Karl Erich Correns (1864-1933) and Austrian botanist Erich Tschermak von Seysenegg (1871-1962).

1901 - De Vries published a paper on mutations.

1902 - American biologist Walter Stanborough Sutton (1877-1916) demonstrated that chromosomes exist in pairs that are structurally similar.

1903 - Sutton proved that sperm and egg cells have one of each pair of chromosomes. 1908 - American biologist Thomas Hunt Morgan (1866-1945) with Alfred H. Sturtevant of the U.S. showed that genes were located on chromosomes; he experimented with Drosophelia (fruit flies) to investigate sex chromosomes, and discovered X and Y chromosomes, sex-linked traits, and crossing-over.

1909 - Danish botanist Wilhelm Ludvig Johannsen (1857-1927) proposed that each portion of a chromosome that controls a phenotype be called a “gene” (Greek: “to give birth to”).

1913 - Alfred Henry Sturtevant (1891-1970) began constructing a chromosome map for Drosophelia (it was completed in 1951 for all four Drosophelia chromosomes).

1919 - Hermann Joseph Muller (1890-1976) of the U.S. experimented with Drosophelia to create more mutant flies.

1941 - George W. Beadle (1903-1989) of the U.S. and Edward L. Tatum (1909-1975) of the U.S. discovered that genes control the production of enzymes.

1944 - Oswald T. Avery (1877-1955) of the U.S. announced that DNA alone is the substance responsible for heredity. 1952 - Francis H. C. Crick (1916- ) of Britain and James D. Watson (1928- ) of the U.S. made a model of the DNA molecule and proved that genes determine heredity.

1950’s - Maurice Wilkins (1916- ), Rosalind Franklin (1920-1957), Crick and Watson discover chemical structure of DNA, starting a new branch of science--molecular biology.

1957 - Arthur Kornberg (1918- ) of the U.S. produced DNA in a test tube.

1966 - The Genetic code was discovered; scientists are now able to predict characteristics by studying DNA. This leads to genetic engineering, genetic counseling.

1972 - Paul Berg (1926- ) of the U.S. produced the first recombinant DNA molecule.

1982 - The first recombinant DNA drug approved by the FDA--genetically engineered insulin for diabetics.

1983 - Barbara McClintock (1902-1992) of the U.S. was awarded the Nobel Prize for her discovery that genes are able to change position on chromosomes.

1988 - An international team of scientists began the project to map the human genome.

The Late 1980’s - The first crime conviction based on DNA fingerprinting, in Portland Oregon.

1990 - Gene therapy was used on patients for the first time.

1994 - The FDA approved the first genetically engineered food--FlavrSavr tomatoes engineered for better flavor and shelf life.

1995 - DNA testing in forensics cases gains fame in the O.J. Simpson trial.

1997 - Dolly the Sheep--the first adult animal clone.

1998 - Three generations of mice were cloned from the nuclei of an adult, eight identical calves were cloned, the rough draft of the human genome map was produced.