#12 - Navigation in animals is defined as...

[glasann]

I'm stuck between B and E because they both seem to weaken it, but actually thought E weakened it more. Below was my thought process. Can you please clarify where I went wrong?

B: I thought that more than being an alternative explanation, it was actually almost an example of the phenomenon of polar bears navigating long distances. Or, just because the reason the polar bear is able to find his way is because it's on his migration route doesn't mean that he's not using navigation skills to find/follow that migration route. I mean seems that long distance navigation skills are needed for migration anyway.

E: this gives us an alternative explanation, if his extreme sensitivity means he can "sniff" his way home, which would mean he's using his sense of smell versus navigation ability. What if he smells his way home? Granted I know smelling 300 miles away is quite nuts, but I'm just focusing on the argument's logic versus real-life facts (i.e. grizzlies can smell up to 20 miles away, which is obviously not 300 because still insanely far!!).

[Adam Tyson]

The problem with answer E, glasann, is that it doesn't tell us that the bears are actually able to smell over that long a distance. Just because they have a good sense of smell and can use it to find familiar territory doesn't mean that THIS bear was able to do that in THIS instance.

But answer B does indicate a problem with this example: this bear was NOT in unfamiliar territory! If "navigation" requires finding your way from unfamiliar territory to someplace familiar but beyond the reach of their senses, then this could not be an instance of navigation if the bear was always in familiar territory. If she knew where she was all along, it's not an example of navigation!

[teddykim100]

Hello,

I can see the reasoning perfectly, as we want to point out problems with the scientists' evidence of using this polar bear as an example,

however, since Answer Choice (E) says that "Polar bears" often rely, meaning that it is a general statement about polar bears (meaning that this sense of smell could apply to our bear in the example), can't we say that this weakens in that it demonstrates our example animal DOES indeed use their senses to find familiar territory?

I'd like to correct the reasoning here. I know it is wrong, but I cannot eliminate that possibility. After all, if it is true polar bears rely on their noses to find familiar territory, this goes against a portion of our definition of navigation!

I guess in direct response to what you were saying the issue with (E) was, I am getting thrown off by how the test writers included that "extreme sensitivity" in there, because maybe, just maybe, there is the possibility that some animal can actually smell that far.

[Paul Popa]

Hi Teddy,

I'd be happy to help! I would argue that (E) is actually already accounted for by the author in the stimulus, and doesn't actually weaken the argument at all. The stimulus sets up our "scene," so to speak. We have a polar bear starting in an unfamiliar place that is trying to navigate to familiar territory. We're also told that they are far enough away that this familiar territory is "beyond the immediate range of the animal's senses." So, while it may be true that polar bears have an extreme sensitivity to smell that they use to scent out familiar territory, they are still placed far enough away, according to the stimulus, that this sense of smell is of no use to them.

(B), on the other hand, directly weakens the argument because it shows that the bear is actually not in unfamiliar territory, which is necessary in order to make any valid claims about navigation. Hope this helps!