Original: McClintock's research became well understood in the 1960s and 1970s, as researchers demonstrated the mechanisms of genetic change and genetic regulation that she had demonstrated in her maize research in the 1940s and 1950s.
Simplified: McClintock's research became well understood in the 1960s and 1970s, as researchers discovered the mechanisms behind the genetic change and gene regulation that she had shown in her maize research in the 1940s and 1950s.