While many people think James Watson and Francis Crick discovered DNA in the 1950s, they actually discovered the double-helix structure of DNA. The molecule itself was first identified in 1869 by Friedrich Miescher, a Swiss biochemist.
Here's a breakdown of key players in the discovery of DNA:
- Friedrich Miescher (1869): Isolated a substance from the nuclei of white blood cells, which he called "nuclein." This substance was later identified as DNA.
- Phoebus Levene (1919-1931): Identified the components of DNA - sugars, phosphates, and bases - and proposed the tetranucleotide hypothesis, which incorrectly suggested DNA had a repeating pattern.
- Oswald Avery, Colin MacLeod, and Maclyn McCarty (1944): Proved that DNA, not protein, is the genetic material responsible for heredity.
- Rosalind Franklin (1952): Used X-ray diffraction to capture images of DNA that were crucial in determining its structure.
- James Watson and Francis Crick (1953): Based on Franklin's X-ray diffraction images and other research, Watson and Crick built a model of the double-helix structure of DNA.
Important Note: While Watson and Crick were awarded the Nobel Prize for their discovery, Rosalind Franklin's crucial contribution to the work was largely ignored during her lifetime.
DNA wasn't "created" in the sense of being designed by an individual. It evolved over millions of years through natural processes. However, the discovery and understanding of DNA's structure and function represent significant milestones in scientific history.
