DNA Timeline - Timeline

1859: Charles Darwin wrote the book, “On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life.”

1865: Gregor Mendel's work on pea plants helped demonstrate heredity and discovered the laws of inheritance. He worked on the pea plants from 1856-1863 and published in 1865.

1869: Friedrich Meisner was the first to be able to isolate DNA for the first time as a distinct molecule and he calls is "Nuclein."

1879: 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.

1948: Edwin Chargaff helped discover two rules which led to the discovery of the DNA double helix structure.

1909: Phoebus Levene characterized the different forms of nucleic acid, DNA from RNA, and found that DNA contained adenine, guanine, thymine, cytosine, deoxyribose, and a phosphate group.

1909: Phoebus Levene came up with the incorrect theory of the structure of DNA as a tetranucleotide.

1909: Wilhelm Johannsen creates the term "gene" to help describe the Mendelian Theory.

1911: Thomas Hunt Morgan studies the fruit fly chromosomes to help show how the chromosomes carry genes over.

1928: Fred Griffith conducted a series of experiments with pneumonia bacteria and mice identified genetic material, and through these experiments, he was able to find that bacteria are able to transfer genetic information through Transformation.

1944: Oswald Avery, Colin MacLeod, and Maclyn McCarty figured out that DNA is the thing that causes bacterial transformation, and along with that they isolated DNA to find out what genes and chromosomes are made of.

1943: 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.

1951: Alfred Hershey and Martha Chase proved that DNA and not protein was the genetic material. Also, that only the DNA of a virus needs to enter a bacterium to infect it, providing strong support for the idea that genes are made of DNA

1953: Maurice WIlkins studied biological molecules like DNA and viruses using a variety of microscopes and spectrophotometers. He eventually began using X-rays to produce diffraction images of DNA molecules, used by Watson and Crick later

1953: Francis H. Crick and James D. Watson described the double helix structure of DNA, they worked together on a research paper. They receive the Nobel Prize for their work in 1962.

1953: Rosalind Franklin was an X-ray crystallographer whose work was central to the understanding of the molecular structures of DNA, RNA, and viruses

1955: Joe Hin Tjio defines 46 as the exact number of chromosomes in human cells.

1955: Arthur Kornberg and colleagues isolated DNA polymerase, an enzyme that would later be used for DNA sequencing in the future.