#11 - In the last year, biologists have learned that there

[kristinajohnson@berkeley.edu]

The difficulty I have with answer choice E is understanding what "objects" is replacing, how can objects stand in for animals or amphibians?

[Luke Haqq]

Hi Kristina!

You can try replacing "objects" in this answer choice with "amphibians," so (E) would refer to a confusion between "changes in our knowledge of amphibians and changes in the amphibians themselves."

The reasoning in this stimulus is flawed because there could be changes in our knowledge about amphibians (such as how many we know to exist) that are independent of changes in the amphibians themselves (such as how many of them actually exist). It's possible that biologists could learn that there are many more species of amphibians even while the actual number of amphibians is decreasing.

[miriamson07]

Hello,

I find that I often get confused with questions that give me different reasoning methods to choose from, like this one.

I wasn’t sure whether the argument here was cause and effect. I thought that biologists learning that there are more species might be considered a cause, and the environmentalists’ claim being undermined might be the effect. But switching those two around made no sense, so I ruled out C and D.

I’d like to know, though… how do we know for sure whether something is cause and effect?

Thank you!

[miriamson07]

My apologies, I’ve rethought the question and realized I should be asking something slightly different.. The correct answer is that the author confuses a change in what they know about something with a change in the things themselves. But it seems to me that the author doesn’t actually think they’re “changing” the species of amphibians to no longer be eliminated in large quantities by pollution every year. Instead, doesn’t the author assume that the environmentalists’ claim was never true in the first place, and the discovery of more species reveals that their claim was wrong?

In that case, would it be alright for the author to be confusing something they don’t even know they are?

It was hard to explain my thinking here — please let me know if my question makes sense; thank you.

[Adam Tyson]

The change is in the number of species that we know about, Miriam. We now know about a lot more species than we knew about before. The author then concludes that the total number of species in existence is not diminishing due to pollution, that the environmentalists are wrong about that. But of course, the environmentalists can still be right. It's possible that many species of amphibians are going extinct due to pollution. The fact that we now know about more that exist has nothing to do with whether others have disappeared. Our discovery of a particular blue tree frog doesn't mean that a red lizard hasn't gone extinct.