4. Kary Mullis
A 1993 Nobel Laureate in chemistry for his DNA research on the polymerase chain reaction (P.C.R.), Kary Mullis is a frequent lecturer on molecular biology.
The New York Times went so far as to say, “His invention is highly original and significant, virtually dividing biology into the two epochs of before P.C.R. and after P.C.R.”
He currently serves on the advisory board of NORML and has written about his use of marijuana and LSD.

