Self-study
Scientist: Conclusion It seems likely that the earliest dinosaurs to fly did so by gliding out of trees rather than, as some scientists think, by lifting off the ground from a running start. ███████ ███████ ████ █████ ███ ████ ██ ███ ████ ████ ██████ ██████ ████ █████ █████████ ████████████ ██████ ██████ ██████ ██████████ ███ █████ █████ ████ ██ █████████ ████ ██████ ██████████
Summarize Argument
The scientist concludes the first dinosaurs to fly probably glided out of trees, rather than flying from a running start. Why? Because gliding from trees requires only simple wings that are stepping stones, evolutionarily, to the larger wings of later dinosaurs.
Notable Assumptions
The scientist assumes it’s more likely the first flighted dinosaurs had wings for gliding than wings for lifting off. This means assuming wings for lifting off the ground are either less simple than wings for gliding or less of a stepping stone toward the wings of later dinosaurs. It also means assuming there’s no other characteristic of the first flighted dinosaurs that would make it less likely they glided from trees than lifted off the ground.
13.
Each of the following, if █████ ███████████ ███ ███████████ ████████ ███████
a
Early flying dinosaurs █████ █████ █████ ██ ███ ████ ██ ██████
This doesn’t favor the scientist’s argument. It implies the first flighted dinosaurs lived on the ground, which if anything makes it less likely they flew by gliding out of trees.
b
Early flying dinosaurs ███ █████ █████ ███ ████ ████ ████████ ███ █████████
This strengthens the scientist’s argument. It implies the first flighted dinosaurs were capable of climbing trees, which rules out the possibility they were confined to the ground.
c
Early flying dinosaurs ███ ███████ ████████ ████ ████████ ████ █████ ████████ ███ ██████ ███████ ████ ██████ ███████
This strengthens the scientist’s argument. It implies the first flighted dinosaurs had biological characteristics more consistent with gliding than with lifting off from the ground.
d
Early flying dinosaurs ███ ████████ ██ █████ ████ ████ █████ ████ ██████████ ████ █████ ███████ ██ ████
This strengthens the scientist’s argument. It implies the first flighted dinosaurs had toes that would have made it difficult to lift off from a running start.
e
Early flying dinosaurs █████ ██ █ ████ ████ █████ ████ █████████ █████████ █████ ███ █████ ██████
This strengthens the scientist’s argument. It implies the first flighted dinosaurs had a reason to climb trees: to avoid predators. It rules out the possibility those dinosaurs would have gained no advantage by living in trees.