Logical ReasoningDifficulty: Medium

PT140 S3 Q16 Explanation

Zoologist: In the Lake Champlain

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

TopicsStrengthen

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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

Zoologist: In the Lake Champlain area, as the North American snowshoe hare population grows, so do the populations of its predators. As predator numbers increase, the hares seek food in more heavily forested areas, which contain less food, and so the hare population declines. Predator populations thus decline, the hare population starts with the regular cycle of sunspot activity, that activity is probably a causal factor as well.

What this question is testing

Strengthen

Argument

The zoologist sees that hare populations cycle in sync everywhere — and notes that the predator-prey explanation alone doesn't explain why they cycle at the same time across the country. So she points to sunspots: the cycles match up with sunspot activity, so sunspots are probably part of the cause.

Evaluate

This is a "correlation -> causation" argument. Strengtheners come in three flavors: (1) a plausible mechanism for how sunspots could affect hares or predators, (2) tighter, deeper correlation, or (3) ruling out alternative explanations.

The trick on this question: we're looking for the answer that doesn't do any of those. Maybe it's neutral. Maybe it points to an alternative explanation that competes with sunspots.

Goal

Look for the answer that's either neutral or weakens the sunspot link.

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

The question
16.

Each of the following, if true, supports the zoologist's

Answer choices

  1. Strengthens8% picked this

    Reproduction in predator populations increases when sunspot activity indirectly affects hormonal processes

    This provides a causal mechanism. Sunspots affect predator hormones, which affect predator reproduction, which drives the predator-prey cycle. That's exactly the kind of mechanism that would make the sunspot causal claim more credible. So it strengthens, and is wrong on a Strengthen-EXCEPT.

  2. Correct73% picked this

    Local weather patterns that can affect species' population changes can occur both in the presence of sunspot activity

    Why this is right

    This actually undermines the zoologist by pointing to weather as an alternative cause that operates independent of sunspots. If weather can drive population changes both with and without sunspots, then weather — not sunspots — could be the real cause of the synchronized hare cycles. This doesn't strengthen the zoologist's sunspot claim; it raises a competing explanation.

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

  3. Strengthens7% picked this

    Brighter light during sunspot activity subtly but significantly improves the ability of predators to detect

    Another mechanism. Brighter light during sunspot activity helps predators detect hares, which would influence hare populations. That gives a concrete causal pathway from sunspots to the hare cycle, strengthening the zoologist's causal claim.

  4. Strengthens5% picked this

    The variation from cycle to cycle in the magnitude of the highs and lows in snowshoe hare populations is highly correlated with variations from

    This deepens the correlation. Not only do hare cycles match sunspot cycles in timing, they also match in magnitude — bigger sunspot peaks correspond to bigger hare-population peaks. That's a much tighter correlation, which strengthens the case for a causal connection.

  5. Strengthens7% picked this

    Sunspot activity is correlated with increases and decreases in the nutritional value of vegetation eaten

    Yet another mechanism. Sunspots affect the nutritional value of vegetation, which affects hares directly. That's a clean causal pathway from sunspots to hare populations, strengthening the zoologist.

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