1865: Gregor Mendel shows that the characteristics of pea plants are passed along in a predictable way. His discovery begins the science of genetics.
1903: Walter Sutton shows that chromosomes carry the cells units of inheritance.
1911: Thomas Hunt Morgan demonstrates that genes are arranged in linear fashion on the chromosomes of the fruit fly
1944: Oswald Avery, Colin Macleod, and Maclyn McCarty show the substance that Griffith discovered was DNA
1950: Erwin Chargoff analyzes the base composition of DNA in cells. He discoveres that the amounts of Adenine and thymine are almost always equal, as are the amounts of guanine and cytosine
1952: Alfred Hershey and Martha Chase confirm that the genetic material of viruses is DNA, not protein.
1952: Rosalind Franklin records a critical X-ray diffraction pattern, demonstrating that DNA is in the form of a helix.
1953: James Watson and Francis Crick publish their model of the DNA double helix. The model was made possible by Franklins work.
2000: Craig venter and Francis Collins announce the draft DNA sequence of the human genome at a White House ceremony in Washington, D.C. The final version is published in 2003