Passage - General Questions

[kristinaroz93]

Scientists have long known that the surface of the bill of the platypus....
This is a very dense and scientific passage with 2 long paragraphs!

I found a good breakdown of the passage online, however, there is one thing I find confusing that maybe someone on this forum can clear up.

Here is the break down:
1. introduces a phenomenon (nerve endings on the bill of the platypus)
2. provides a use for the phenomenon (locate prey while underwater)
3. provides evidence for that hypothesis (Bohringer's research)
4. points to a weakness in the evidence (locate prey at a distance)
5. fixes the weakness with additional research (Scheich's research)

1)I don't understand point 3 and how Borhinger's research provides evidence for the phenomenon. Bohringer says that "the bill must be the primary sensory organ for the platypus" based on tactile stimulation of pushrods sending nerve impulses to the brain. Is this how she strengthens the idea that the Platypus can locate prey underwater using its bill (i.e. by saying that the bill is their primary sensory organ)? I am trying to connect the dots between her research and how it strengthens the phenomenon mentioned in point 2 of the break down.
2)Also, is Borhinger the one who discovered the two sensory receptors?
3)I found this to be confusing as well: "Only recently, however, have biologists concluded on the basis of new evidence that the animal uses its bill to locate its prey while underwater.." lines 3-6. So Is what happened that they initially hypothesized about the platypus being able to locate its prey while underwater using its bill because it was observed that the animal's eyes, ears and nostrils were not working when underwater. But then the new evidence of the receptors and B's research allowed for a more definitive conclusion of this same idea that, yes, it is actually the case that the platypus rely solely on their bills underwater to find their prey given how sophisticated their bills are. (Essentially my understanding is that the eyes, ears, and nostrils reasoning was the basis for the formation of hypothesis (P finding prey underwater with their bill) to which the discussion of the new evidence and B's research proved the hypothesis as being true).
(This passage is really confusing me, I hope hope someone can help me=) )

[Anthony Esposito]

Well Kristina, let's just say that if nothing else, I just learned a lot about the duckbilled platypus

Let me see if I can answer your questions one by one:

1) Bohringer's believes that the bill must be the primary sensory organ for the platypus because of a number of reasons. When the mechanoreceptors (tiny pushrods) of the bill are stimulated, this causes a very large part of the platypus' brain to react, a larger part than reacts from input from its limbs, eyes, and ears. Also, the info in lines 20-29 also support Bohringer's idea that the bill must be the primary sensory organ for the platypus.

2) It is hard to tell from the wording of lines 14-20 whether or not some other groups of scientists discovered that tactile stimulation of the pushrods sends nerve impulses to the brain and then Bohringer used that knowledge to conclude that the bill must be the primary sensory organ for the platypus or if it was Bohringer herself that both made the initial discovery about the tactile sensitivity of the pushrods and then used it to conclude that the bill must be the primary sensory organ for the platypus.

Thankfully, question #2 above does not have to be determined to answer any of the questions that go along with the passage. Remember: You only get points for understanding (or being able to point to) the parts of the passage that the LSAT asks you about in the questions section.

3) Basically, the old thinking was probably that the platypus used things other than its bill (eyes, ears, nostrils, etc.) to locate prey underwater. However, two new discoveries, the learning about the mechanoreceptors (pushrods that respond to tactile [aka feeling] pressure and electroreceptors (which respond to weak electronic fields) let us know postulate that the bill is integral to locating prey underwater.

Hope that helps!
Anthony

[kristinaroz93]

Hi Anthony,

Thank you so much for your response, I really appreciate it. I gained a lot of insight from your response, but I do not think your response really answers my number 1 and 3, or rather I still feel kind of confused about them. =/

1) How does Bohringer's assertion that a bill is a primary sense organ contribute to the argument at large? Is because something a primary sense organ (i.e. the bill), that we can automatically assume it is used to locate prey under water? And does everything B essentially say just in the pursuit of showing the bill as being a primary sense organ?

3) Oh wait I think I get this one! The biologists found new evidence (the receptors) to show how integral the bills are in finding prey. But the fact that eyes,nose,and ears are closed further helped prove that idea! I thought it was the basis of the hypothesis but it was an addition to accurately conclude what the evidence already showed. Is that it?

[Emily Haney-Caron]

Hi Kristina,

For 1: It contributes to the argument at large by explaining how the bill is used to locate prey nearby the platypus. It is the primary sensory organ (and, therefore, presumably used to locate prey, because it is how the platypus primarily gets information about the world around it - but we have lots more support for that as well), and when it senses something it creates a snapping motion clearly related to consumption of prey.

For 3: Yep, you're on the right track.

I also think you might have gotten yourself a bit tripped up overthinking this one; you want to focus on being able to quickly take away what you need to know from a passage, without getting bogged down!

Good luck with studying!

[lanereuden]

Hey, it says: Scheich then discovered that the tail flicks of
Does it mean to say flicks off?
Is this a typo for the oh so prim-and-proper LSAC writers? Or am I indeed illiterate?

[Erik Shum]

Hi Lane,

Do you mean at line 51?

It definitely means "tail flicks of."

The platypus's prey, the shrimp, flick their tails and in doing so send off electrical signals that would trigger the search-and-attack response from the platypus.

If it were "flicks off," the platypus would be using its tail to flick off "freshwater shrimp, a common prey of the platypus" which would be reversed predator-prey behaviour.