No. 4 – DNA: Not So Important
DNA was discovered in 1869, but for a long time, it was kind of the unappreciated assistant: doing all the work with none of the credit, always overshadowed by its flashier protein counterparts.
Even after experiments in the middle part of the 20th century offered proof that DNA was indeed the genetic material, many scientists held firmly that proteins, not DNA, were the key to heredity. DNA, they thought, was just too simple to carry so much information.
It wasn’t until Watson and Crick published their all-important double-helical model of the structure of DNA in 1953 that biologists finally started to understand how such a simple molecule could do so much. Perhaps they were confusing simplicity with elegance.