First you should know that when I sit in on classes like this, I take my queues from the professor as regards asking questions during a class. In this particular class, where the opportunity for questions arose, I would have been able to ask but I chose to hold my questions until after class.
The topic for the day was the concept of rarity. In case it isn't obvious rarity means a relatively low population count (based upon biomass) in a geographic area. (Lions are rare on Long Island, but not in Kenya.) Rarity was discussed as a predictor of extinction.
Now here I might have asked a question, but I couldn't know whether it had been discussed earlier in the semester. My question was: You discuss rarity in terms of extinction, but isn't it a really big problem with the whole concept of speciation too? (Of course it is, as the professor acknowledged. I was rather surprised that it didn't seem to be part of his syllabus.)
My second question, or set of questions, had nothing to do with his topic for the day. I asked: Do you believe evolution occurs gradually over a long time; or rather suddenly in steps. Like most he opted for gradually. Then I asked whether he believes in chromosomes, which of course he did. So I asked him how we evolved from 22 chromosome pairs to 23 chromosome pairs gradually. He didn't even try to answer.
ML/NJ