Question

jan gimsa, robert sleigh, and ulrike gimsa have hypothesized that the sail - like structure running down the back of the dinosaur spinosaurus aegyptiacus improved the animals success in underwater pursuits of prey species capable of making quick, evasive movements. to evaluate their hypothesis, a second team of researchers constructed two battery - powered mechanical models of s. aegyptiacus, one with a sail and one without, and subjected the models to a series of identical tests in a water - filled tank. which finding from the model tests, if true, would most strongly support gimsa and colleagues hypothesis? choose 1 answer: a the model with a sail took significantly longer to travel a specified distance while submerged than the model without a sail did. b the model with a sail displaced significantly more water while submerged than the model without a sail did. c the model with a sail had significantly less battery power remaining after completing the tests than the model without a sail did. d the model with a sail took significantly less time to complete a sharp turn while submerged than the model without a sail did.

Explanation:

Gimsa and colleagues' hypothesis is that the sail - like structure improved the dinosaur's success in underwater pursuits of prey that can make quick, evasive movements. A key aspect of successful pursuit of evasive prey is the ability to make quick, sharp turns. If the model with the sail can make sharp turns more quickly (as in option D), it supports the idea that the sail aids in underwater pursuits.

• Option A: A model with a sail taking longer to travel a distance while submerged would go against the idea of the sail aiding in pursuits (since slower movement is not beneficial for catching evasive prey).
• Option B: Displacing more water does not directly relate to the ability to pursue evasive prey. It could potentially be a negative (more water displacement might mean more drag in some cases, but it's not clearly related to pursuit success).
• Option C: Having less battery power remaining after tests is not relevant to the sail's role in underwater pursuit of prey. It's about energy consumption of the model, not the functionality of the sail for the hypothesized behavior.

Answer:

D. The model with a sail took significantly less time to complete a sharp turn while submerged than the model without a sail did.