Events
1859
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.”1865
Discovery: Heredity Transmitted in Units
Gregor Mendel’s experiments on peas demonstrate that
heredity is transmitted in discrete units.1869
Discovery: DNA Isolated
Frederick Miescher isolates DNA from cells for the first time
and calls it “nuclein”.1879
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 1882.1900
Discovery: Rediscovery of Mendel’s work
1902
Botanists DeVries, Correns, and von Tschermak independently
rediscover Mendel’s work while doing their own work on the
laws of inheritance.1902
Discovery: Chromosome Theory of Inheritance
Walter Sutton observes that the segregation of chromosomes
during meiosis matched the segregation pattern of Mendel’s1909
Discovery: The Word Gene is Coined
Wilhelm Johannsen coins the word “gene” to describe the
Mendelian unit of heredity.1911
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.1941
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.1944
Discovery: DNA Transforms Cells
Oswald Avery, Colin MacLeod, and Maclyn McCarty show
that DNA (not proteins) can transform the properties of cells --
thus clarifying the chemical nature of genes.
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