介绍:
Conversation2
Narrator
Listen to a conversation between a student and his biology professor.
Student
Professor Landrea.
Professor
Hi, Dennis. You are right on time. Come on in and have a seat.
Student
Great! Thanks.
Professor
So like I told you in class, I just wanted to take a few minutes to meet with everyone to make sure your class presentations for next week are all in order and coming along well. And as you know, you are supposed to report on some area of recent research in genetics, something…you know…original.
Student
Well, I think I found just the thing! It actually occurred to me a couple nights ago while I was eating dinner in the cafeteria. Tell me professor, do you like broccoli?
Professor
Broccoli? You mean the vegetable broccoli?
Student
Yeah.
Professor
Well, I guess not really.
Student
Me neither. I have never liked it or most other vegetables for that matter…Brussels sprouts, asparagus, cauliflower…you name it. They just taste bitter and…well…nasty to me. My mother always called me a picky eater.
Professor
OK…And?
Student
And so I got to wondering: I mean, I am obviously not the only person like this. So is this just because of some…like trauma from our childhoods? Some bad experience we’ve had with some vegetables? Or could there be some genetic explanation for why some people are picky eaters and others aren’t?
Professor
OK. I see. Well, I suppose it’s a possibility.
Student
Actually, it turns out it’s more than a possibility. I started doing some research in the library that night and I found out that a biologist at the National Institutes of Health has been looking at that very question recently.
Professor
Well, I guess that’s not too surprising. And this is great stuff actually. So what’s the verdict?
Student
Well, this guy seems to have discovered a particular gene that actually makes it possible for people to taste the bitterness in certain green vegetables. But people who have a mutation in that gene cannot taste the bitterness.
Professor
Well…that’s certainly fascinating! But…so this biologist is basically claiming that people who like to eat these vegetables actually have some sort of sensory deficit? Sort of makes us picky eaters than normal ones, doesn’t it? I mean, that’s kind of turning things on their head, isn’t it?
Student
Well…then again, it wouldn’t be the first time, would it? Think of it this way: humans originally needed to have a stronger sensitivity to bitter-tasting foods so they could learn what plants were good for them and which ones might be poisonous. But at some point, as people figured out what they could safely eat, this need became less crucial and a segment of the population lost that ability.
Professor
OK. Well, you make a compelling case. I can’t wait to hear more about this when you deliver your report.
