Original: George Ledyard Stebbins , Jr. ( January 6 , 1906 -- January 19 , 2000 ) was an American botanist and geneticist who is widely regarded as one of the leading evolutionary biologists of the 20th century .
Simplified: In 1935 , Stebbins was offered a genetics research position at the University of California , Berkeley working with geneticist E.B. Babcock .