Watson and Crick's Discovery

James Watson and Francis Crick discovered the structure if DNA. Upon this discovery, DNA has revolutionized evolutionary biology. Researchers realized mutations change the spelling of the cookbook (when a cell divides, the double helix is unzipped and the DNA is replicated). A single base pair may change, or a set of genes may be duplicated. The mutations that confer a selective advantage to an individual become more common over time, and ultimately the mutant genes may drive the older versions out of existence.