Teaching botany to physicists

Physicists are pretty bright guys, but they really don't have a clue about biology.  In the USA science curricula do a weird thing.  If you study biology, you generally have both a chemistry requirement, which is sometimes quite substantial, and a physics requirement.  Geology is left out of the equation although in many field geology is more relevant than physics.  Chemistry curricula have their students take physics, but never biology, and this is rather strange considering the broad interface that exists between the two fields.  Physics majors usually take math. This is why biologists in general know more about the physical sciences than they do about biology. In an effort to improve collegiality, biologists are being invited to give an informal lunchtime seminars.  It was pretty strange because they asked a ton of questions, mostly that had nothing to do with my research, they just wanted to hear a biological perspective.  "Are botanists alarmed/worried about global warming?"  Yes.  "What do you think about the denialists?"  It worked well for big tobacco, so the same people are using the same strategy.  It's easier to cast doubt on the science than it is to argue policy.  "What about evolution?"  What about evolution?  It happened, it's happening, we do our best to understand how.  "How do you know if plants are related?"   Shared characters, some external, some internal, some purely molecular. "If a plant grew on the west coast, but could grow on the east coast, how long would it take for it to get there?"  A flight from Portland to New York takes about 4 hours.  "If ginkgo was nearly extinct, how come you now see them all over the place?"  Seeds from a couple of small surviving populations were collected and the tree became a cultivated species and we've, humans, have moved it everywhere.  "So if it can live almost anywhere, why was it nearly extinct, and how come it was once widespread as the fossils show?"  Good question, we don't know, but it lives almost anywhere with our human assistance.  It hasn't escaped into the wild anywhere. While ginkgos were widespread in the fossil record, it wasn't this species, but a whole lineage of ginkgo related plants.   "Why doesn't ginkgo have any diseases?"  Hmm, so physicists have an inordinate interest in ginkgos, why?  Well, when you almost become extinct, the organisms that depend upon you have a very tough if not impossible time surviving.  The population of ginkgos gets to small to support other populations.  "Why do you go to the tropics?"  Tropical food is great, but generally biologists love the tropics because of the diversity, which means lots of interactions, complexity.  In the specific my research is centered around tropical trees in the magnoliid lineage. 
It was an interesting exchange, but many of the questions showed their lack of biological understanding.  So hopefully this was helpful.