Dr Johnson was great. It was really interesting to think of the Earth dotted with tropical forests from pole to pole. He posed some great questions for research. I am not a specialist in paleobotany, but his lecture was very approachable. I understood what his research was about, why he was doing the research (impacts on info on climate change), and where he was going with the research next. I also like that he said scientists should put more of a priority on communicating science to the public. Thanks so much for having him - cool to see the Dir. of the Smithsonian NHM!