PT10.S1.Q16 - a favored theory to explain

skrishnan

I'm having trouble understanding the logic behind this one. I feel like i'm missing something basic. Got it wrong during BR too

BinghamtonDave

This at bottom is a weakening question. I have sketched two (badly drawn) diagrams below. The first is what the stimulus tells us. The stimulus actually tells us that the proposed cause of the extinction was an asteroid that hit the earth, scattered this layer of dust and set in motion the extinction of the dinosaurs. Visually represented that sequence of events would look like this:

The assumption with the first theory is that the dinosaurs died on top of the dust because the dust preceded their death. We know this because the alleged cause of their death was the asteroid and the asteroid caused the dust to occur "contemporaneously."

How do we weaken that theory? What if the bulk of the dinosaur deaths we had actually occurred below and therefore before the dust dropped? That is what (E) says in an oddly difficult way. In the following diagram we have a visual depiction of what that would look like:

Here we have the dinosaurs dying under the layer of dust. Meaning, they were already dead when the dust settled.

(E) doesn't bode well for the theory. How can it be that the dinosaurs died before something that was supposed to be the cause of their death?

I hope this helps.
David

skrishnan

Thanks David!
Love the illustrations!
I completely understand your explanation and would probably reach E by the process of elimination. However, I was a little confused by what they meant by geological level. How can we conclude that the dust is on the top layer?
I'm sorry if it's a dumb question, but I've never had such a hard time being convinced of an answer even after BR!

Climb_to_170

@skrishnan said:
However, I was a little confused by what they meant by geological level. How can we conclude that the dust is on the top layer?

This is not a dumb question! Old PTs often rely more heavily on outside knowledge to answer the curvebreaker questions than the newer PTs.

In geology, there's a concept called "stratigraphy" which is the idea that, if you were to dig down in a certain area, you would come across certain distinct layers or "geological levels" (called strata) as you dig. The layers you come across as you dig deeper into the Earth are older than the previous layers and younger than those below. The stimulus is saying one of these strata/"levels" is a worldwide layer of dust dating back to when the asteroid strike is said to have occurred.

Here is a short video explaining the very basics of stratigraphy which is worth having an understanding of for the LSAT: