Who discovered transformation in bacteria?

Frederick Griffith discovered transformation in bacteria through his pioneering experiments with Streptococcus pneumoniae in 1928. He conducted a study where he introduced heat-killed virulent bacteria to non-virulent strains. He observed that the non-virulent bacteria transformed into virulent forms, indicating that some "transforming principle" from the dead bacteria had been taken up by the living cells. This crucial finding contributed significantly to our understanding of genetic material and laid the groundwork for future research in molecular biology and genetics.

The other individuals mentioned played significant roles in the field of biology and genetics, but their contributions were focused on different aspects. Charles Darwin is best known for his theory of evolution through natural selection. Avery MacLeod later built upon Griffith's work in the 1940s by demonstrating that DNA is the transforming principle, while Erwin Chargaff is famous for his rules regarding the base composition of DNA, which also contributed to our understanding of molecular biology, but did not directly discover bacterial transformation.