Oswald Avery: The Researcher Who Identified DNA as the Hereditary Material

On October twenty-first, eighteen seventy-seven, Oswald Theodore Avery was born in Halifax, Canada. He was a physician and microbiologist, and his academic field was molecular biology and immunology.

Avery is known for one of the most crucial experiments in the history of biology, which solved the fundamental question: what is the chemical substance that carries genetic information? In the nineteen-thirties and forties, Avery worked on transforming pneumococcus bacteria. Through a series of elegant and controlled experiments, he and his team demonstrated that when a substance called deoxyribonucleic acid – DNA – was transferred from one strain of bacteria to another, it could permanently alter the heritable traits of the recipient bacteria. This "Avery-MacLeod-McCarty experiment," published in nineteen forty-four, was the first direct evidence that DNA, and not proteins, was the hereditary material. Although the discovery was not immediately embraced by the entire scientific community, it laid the very cornerstone for the age of molecular biology and inspired scientists like Watson and Crick to unravel the structure of DNA.