History

==[|The History of DNA] ==

[[image:http://history.nih.gov/exhibits/nirenberg/images/photos/01_mendel_pu.jpg width="169" height="196" align="center" caption="Photograph of Gregor Mendel."]]
Gregor Mendel came up with the idea of heredity. He conducted experiments with pease plants to try to understand how traits are inherited from parents to their children. It took 34 years for the rest of the scientific community to catch up and to accept his theories. He wrote a book, //**Experiments with Plant Hybrids**//, in which he explained how traits were inherited and it has become one of the best written works in science history. 1900 ** The process of genetics was created when Hugo DeVries, Erich Von Tschermak, and Carl Correns each one researched scientific literature for their own original work. 1935 ** Andrei Nikolaevitch Belozersky established DNA in it's pure state for the first time.
 * 1865 **

James Watson and Francis Crick proposed the double-stranded, helix, anti-parallel model for DNA. 1958 ** Coenberg discovered and isolated DNA polymerase, which became the first enzyme used to make DNA in a test tube.
 * 1953 **

The genetic code was "cracked" by Marshall Nirenberg, Heinrich Mathaei, and Severo Ochoa.
 * 1966 **

The first successful DNA cloning experiments were performed in California.
 * 1972 **

For the first time, scientists successfully transferred DNA from one life form into another.
 * 1973 **

The NIH released the first guidelines for recombinant DNA experimentation. The guidelines restricted many categories of experiments. Studies by David Botstein and others found that when a restrictive enzyme is applied to DNA from different individuals, the resulting sets of fragments sometimes differ markedly from one person to the next, these are call Restriction Fragment Length Polymorhisms (RFLPs). 1980 ** Kary Mullis and others at Cetus Corporation in Berkeley, California, invented a technique for multiplying DNA sequences by the polymerase chain reaction. PCR has been called the best new technique in molecular biology in the 1980s. 1984 ** Alec Jeffreys introduces DNA fingerprinting to identify individuals.
 * 1976 **
 * 1978**

**1985** Genetic fingerprinting enters the court room.

Creation of the National Center for Human Genome Research, headed by James Watson, which will oversee $3,000,000,000 U.S. in an effort to map and sequence all human DNA by the year 2005.
 * 1989 **

**1992** The U.S. Army begins collecting blood and tissue samples from all new recruits to try to create a better system of identification for soldiers killed in war.

**1993** An international research team, led by Daniel Cohen in Paris, produced a rough map of all 23 pairs of human chromosomes.

Former football player O.J. Simpson is found not guilty in a murder trial in which DNA fingerprinting played a huge role.
 * 1995 **

Researchers at Scotland's Roslin Institute report that they have cloned Dolly, a sheep, from the cell of an adult ewe. Also, leading geneticists expressed shock and dismay as word spread of the US Patent and Trademark Office announcement that it would allow patents on expressed sequence tags, short sequences of human DNA that have proven useful in genome mapping.
 * 1997 **

**1998** A rough draft of the human genome map was produced, showing the locations of more than 30,000 genes.

Scientists finally cracked the human genetic code. This took 10 years of research and over 1,000 researchers that could understand the diagnosis and treatment of diseases that were once considered to not have a cure. Decoding the 3 billion chemical letters in human DNA is one of the biggest milestones in U.S. history.
 * 2000 **