Scientist: It seems likely that the earliest dinosaurs to fly did so by gliding out of trees rather than, as some sci...

shunhe on October 6, 2020

Hi @jingjingxiao11111@gmail.com,

Thanks for the question! So let’s take a look at what the stimulus is telling us. We’re told that it seems likely that the earliest flying dinosaurs glided out of trees and didn’t lift off the ground from a running start. In general, we’re told that animals that glide from trees can fly with very simple wings. And we’re also told that these simple wings represent evolutionary middle stages toward developing the large wings that we associate with flying dinosaurs.

So now we’re asked to find something that DOES NOT strengthen the scientist’s argument. So we want something that either weakens the argument, or is irrelevant to the argument. What’s the conclusion here? It’s that the earliest dinosaurs glided out of trees and didn’t lift off from the ground.

Now let’s take a look at (A). It tells us that early flying dinosaurs built their nests at the base of trees. Why does this have to do with the conclusion? It might help if we were told that the nests were in the trees. But the nests being at the bases of trees doesn’t really help us think that the dinosaurs glided from (presumably at least somewhat up) trees at all. So (A) doesn’t strengthen, it’s just kind of irrelevant, especially compared to the other answer choices, and that makes it the correct answer choice.

Hope this helps! Feel free to ask any other questions that you might have.