Scientists once believed

Answer choices

1. A

   No Impact22% picked this

   Was the ratio of the head size of the recently discovered dinosaur to its body size the same

   It seems like we already know that the ratio wasn't the same, since we know this skeleton dinosaur had the big T-Rex head but was 1/100 the weight (so probably had a smaller body). Even if we didn't already know that the ratio wasn't the same, saying that the ratio "wasn't the same" isn't a great objection. On Necessary Assumption, the concept of "same" is almost always wrong. When you negate it, you get "different", which is too unspecific to have clear impact. If you replace the word "same" with "identical", it's easier to hear how unimportant this distinction is. Does the ratio need to be identical in order for this skeleton to qualify as noteworthy counterevidence? Doesn't seem like identical is necessary. If it were 98% the same, we'd still be intrigued by how to explain this skeleton.

   22%
2. B

   Correct53% picked this

   At what stage in its life did the recently discovered

   Why this is right

   If we're unsure about the potential usefulness of this question, consider extreme answers: what if it died late in life, as a geriatric dinosaur? What if it died very early in life, as a dino-toddler? That second one would actually be a way to "make an excuse" for this skeleton. If we found the skeleton of a baby T-Rex, it would have the characteristic T-Rex features but be 1/100 the weight. This is one of the weirdest correct answers ever. It lives in infamy as the "baby T-rex" question. One annoying aspect of this problem is that this skeleton is identified in the paragraph as an "earlier" dinosaur, which seems to mean that this skeleton predates when T-Rex was known to exist. So this isn't really a baby T-rex, but whatever this earlier species is, it looks like a possible precursor to T-rex. The important point remains the same: the T-Rex features might still have been an adaptation to big size and weight. The fact that this skeleton was 1/100 the weight could be because it was still a tiny, growing child version of the species.

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

   53%
3. C

   Too Strong: largest / heaviest2% picked this

   Was T rex the largest and heaviest

   Does it matter whether T-rex is the #1 heaviest / largest vs. the #2 heaviest / largest? No, that distinction would have no impact on the argument.

   2%
4. D

   Weak Impact19% picked this

   Was the species to which the recently discovered dinosaur belonged related

   If we say that the species was related to T-Rex, it still serves as a potential counterexample -- given that this skeleton had the T-rex "family" features but didn't have massive size or weight, it would imply that these features aren't an adaptation to size and weight. If we say that the species was not related to T-Rex, we have something more like an objection. "That skeleton doesn't disprove what we said about T-Rex's features being an adaptation to size/weight ... it's just a skeleton from an unrelated species!" LSAC must consider that objection to be weaker than the one we get from saying the skeleton was just a baby. It kind of goes back to the evolutionary common sense we talked about in the analysis: if gills are used by some species for breathing underwater, we still doubt that another species developed the same adaptation for a completely different reason. There are a lot of unrelated species, for example, that have spikes or armor on their backs, as an adaptation to make it harder for predators to eat them. There are tons of unrelated species that all have similar looking eyes, that are all adaptations for the sake of vision.

   19%
5. E

   Out of Scope: size of prey4% picked this

   Did the recently discovered dinosaur prey on species as large as those that T

   The size of this mystery animal's prey is too remote from what we're analyzing. Can we weaken the argument by saying that this mystery animal preyed on animals just as big as T-rex's prey? Can we weaken by saying that it ate smaller animals? I'm not seeing how that would explain away the fact that it has T-rex's features but not T-rex's size.

   4%