Scientist: It seems likely

Answer choices

1. A

   Correct73% picked this

   Early flying dinosaurs built their nests at the base

   Why this is right

   If this answer can be said to have any impact, it is weaker than that of the other four. Ironically, almost all of us initially feel like, "Yup, (A) strengthens. I want to strengthen the idea that the first flying dinosaurs glided out of trees. (A) talks about dinosaurs and trees." But how does the fact that they built nests at the base of trees make it more plausible that they glided out of trees? Can they even climb up the trees? If they built their nests at the base of a tree, it seems like they couldn't climb the tree. No mama wants her nest all vulnerable at ground level. Nests are hidden and sheltered and protected to whatever extent the parents are capable of. If the nests were in the trees, that would strengthen. We could place dinosaurs at "the scene of the crime" ... i.e. in order to glide out of a tree, you need to be up in a tree in the first place. But this answer either suggests nothing about their ability to climb a tree, or suggests the opposite of what we want.

   Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

   73%
2. B

   Strengthens3% picked this

   Early flying dinosaurs had sharp claws and long toes suitable

   This helps the plausibility of the "gliding out of trees" hypothesis by establishing that dinosaurs could feasibly climb up a tree, in order to have a launching spot from which to glide.

   3%
3. C

   Strengthens9% picked this

   Early flying dinosaurs had unusual feathers that provided lift while gliding, but little control

   This helps to give the "gliding out of trees" hypothesis a comparative advantage over the "lift off ground" one. It's saying that the first flying dinosaurs had feathers that were more conducive to gliding than to having any control during lift off.

   9%
4. D

   Strengthens5% picked this

   Early flying dinosaurs had feathers on their toes that would have interfered with their

   This hurts the plausibility of the "lifting off the ground" alternative hypothesis, by making it seem implausible that they could have run fast enough to take off.

   5%
5. E

   Strengthens9% picked this

   Early flying dinosaurs lived at a time when their most dangerous predators could

   This helps the plausibility of the "gliding out of trees" hypothesis by establishing that dinosaurs had an incentive to evolve adaptations that would allow them to climb up trees. Any dinosaurs whose mutations allowed them to climb trees would have great protection from the most dangerous predator in that dinosaurs habitat. A survival advantage like that would presumably be selected for by evolution. In other words, this answer increases the plausibility that dinosaurs could climb trees by pointing out a compelling selection pressure in the dinosaurs environment for tree-climbers.

   9%