DNA Structure (1953)

The determination of DNA's double helix structure in 1953 by Watson and Crick, leveraging Rosalind Franklin's X-ray crystallography data, is the most consequential biological discovery of the 20th century, outperforming #5 (the structure of the ribosome) in scope. This breakthrough explained how genetic information is stored and transmitted, launching molecular biology and genetic engineering. It made possible the biotech industry, genome sequencing, mRNA vaccines, and CRISPR gene editing. Today, 70% of all biomedical research relies on this discovery, underpinning advances from personalized medicine to agricultural biotechnology.