Narrator: Now listen to part of a lecture on the topic you just read about.
Professor: Well, actually, very recent research has suggested that, in fact, the multi-factor theory better explains the explosion in colony collapse disorder in many parts of the world, after all.
First of all, several studies have been conducted by academic and government institutions to try to explain the causes of colony collapse disorder. All the studies concluded that no single factor—including exposure to any specific type of pesticide—was notably more correlated with colony collapse than other likely factors.
Second, even though a certain pesticide may play a large role in North American honey bee colony collapse, it can’t be the reason for recent problems in Europe. After all, the European Union banned the use of these pesticides in 2013—but problems with colony collapse persist there. Also, there are some reports of a spike in colony collapse on farms that don’t use any pesticides at all.
Finally, there is the fact that honey bees are known to be sensitive to a wide variety of external stressors. This includes climate change—especially in warm climates… the possibility of viruses spreading among bee populations in certain parts of the world… and a global outbreak of a parasitic mite that is known to be lethal to honey bee populations. All of these various factors add up. And… while honey bee colonies can generally survive multiple stressors in small doses, it is also known that once the combination of stressors grows too large, the bee colonies… well, they just start giving up! We need to face the fact that the sum total of stressors to bees—from deforestation, pollution, global warming, pathogens, and parasites, as well as pesticides—may have finally gotten to the point where honey bees simply cannot cope anymore.
The lecturer is arguing against the passage, which states that pesticide theory is the likely-most cause of the rise of colony collapse disorder of honey bees. The lecturer believes that multi-factor theory is the primary cause for honey bees abandoning of their colonies.
The passage claims that the chemicals in pesticides have caused direct harm to the honey bees, which supports the proof of the pesticide theory. The passage also talks about fungicides making colonies lose function. However, the lecturer weakens this argument when discussing the European ban of pesticides. Even after the ban of pesticides of Europe, colony collapse disorder continued to happen. Also, there has been reports of colony colapse disorder in places where pesticides are not used. That means that pesticides probally were not the main contributor to colony collapse disorder, according to the lecturer.
The lecturer believes that multi-factor theory makes the most sense because of bee sensitivity the many external factors they have faced, such as climate change and parasites. According to the lecturer, when honey bees are faced with too many stresses in combination, they cannot handle all of the stresses and will give up and abandon the colony. The combination of factors (multi-factor theory), the lecturer believes, is the primary cause of the rise in colony collapse. Pesticides are just one of these factors, as opposed to the main factor.
The student thoroughly addresses the second and third points made by the lecturer. His response could perhaps be improved by addressing the first point. But because he does a strong job of explaining the other points, he can still earn a good score on his response.