Logical ReasoningDifficulty: Medium

PT5 S3 Q6 Explanation

As air-breathing mammals, whales

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsStrengthen

Keep going in LSAT Lab

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Free to start

Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Stimulus

As air-breathing mammals, whales must once have lived on land and needed hind limbs capable of supporting the mammals’ weight. Whales have the bare remnants of a pelvis. If animals have a pelvis, we expect them to have hind limbs. A newly discovered fossilized whale skeleton has very fragile weight on land. This skeleton had a partial pelvis.

What this question is testing

Strengthen

Your task

Find the choice that makes the argument's conclusion more likely to be true.

Common trap

Answers that are consistent with the argument but add no real support, or that strengthen a claim the argument doesn't make.

Winning move

Locate the gap between evidence and conclusion, then pick the choice that closes it.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
6.

If the statements above are true, which one of the following, if also true, would most strongly support the conclusion that the fragile hind limbs are remnants of

Answer choices

  1. Correct75% picked this

    Whale bones older than the fossilized hind limbs confirm that ancient whales

    Why this is right

    By stating that whale bones older than the fossilized hind limbs confirm ancient whales had full pelvises, this strongly suggests that at one point in time, whales had fully functional pelvises with weight-supporting limbs. That makes it more plausible that these fragile hind limbs came AFTER the stage when whales walked on land and BEFORE whales became fully aquatic creatures.

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

  2. Opposite (if anything)6% picked this

    No skeletons of ancient whales with intact hind limbs capable of supporting the mammals’ weight

    This seems to hurt the story that whales once lived on land. We have no evidence of limbs that would made them capable of walking on land.

  3. No Impact2% picked this

    Scientists are uncertain whether the apparently nonfunctioning limbs of other early mammals derived from once-functioning

    Mentioning uncertainty about nonfunctioning limbs in other mammals doesn't contribute evidence about whale ancestors specifically. This creates ambiguity regarding evolution patterns but does not clarify the connection for whales.

  4. Weakens (if anything)16% picked this

    Other large-bodied mammals like seals and sea lions maneuver on beaches and rocky coasts without

    This would potentially help someone argue that the fragile hind limbs aren't a sign of life on land, but maybe just a habit of temporarily resting on rocks or beaches.

  5. No Impact1% picked this

    Some smaller sea-dwelling mammals, such as modern dolphins, have no visible indications

    The fact that modern dolphins don't have visible hind limbs (neither do whales) doesn't tell us anything about what to make of these fragile hind limbs that whales apparently once had.

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free