© CLAUS LUNAU/SCIENCE SOURCE
In the early 1900s, most researchers believed that DNA was a “stupid molecule,” too simple to be of any value in the transmission of life. Instead, scientists championed proteins, with their variability and complexity, as the key component of heredity. Then in the early 1950s, geneticists Alfred Hershey and Martha Chase, working with bacteria-infecting viruses called bacteriophages, confirmed DNA as the informational unit of the cell. The now-famous Hershey-Chase experiments tracked the movement of viral DNA into bacterial cells, as well as the fate of the proteins on the viral capsid, and demonstrated that viral DNA is necessary and sufficient for phage replication, implicating DNA as the molecule needed for every organism’s reproduction.
In 1953, James Watson, Francis Crick, and Rosalind Franklin solidified Hershey and ...
