Final answer:
Avery, MacLeod, and McCarty discovered that DNA is the molecular basis of heredity, transforming the understanding of genetics.
Step-by-step explanation:
Oswald Avery, Colin MacLeod, and Maclyn McCarty discovered that DNA was the molecule responsible for genetic transformation. Their groundbreaking research in the 1940s directly followed up on Frederick Griffith's experiment which showed that living bacteria could be transformed by an unknown substance from dead bacteria. Avery, MacLeod, and McCarty conducted experiments which showed that when DNA was degraded, the R strain of bacteria could not be transformed, meaning it remained harmless. However, when other components such as proteins were degraded, the bacteria could still be transformed. This led to their conclusion that DNA was the material of heredity, upending the then-prevailing theory that proteins were the genetic material.
The reluctance of the scientific community to accept these findings prevented Avery, MacLeod, and McCarty from receiving recognition commensurate with the significance of their work, which paved the way for future discoveries in genetic research. Ultimately, evidence from subsequent experiments, like those of Hershey and Chase, provided additional proof that DNA, and not protein, was the genetic material.