LSAT (Law School Admission Test)Logical ReasoningMedium
Biologist: 'The recent increase in the population of a certain invasive beetle species is a direct result of the abnormally warm winters we have experienced over the past five years. These warmer temperatures allowed more beetles to survive through the winter months.'
- AThe beetle species is also known to reproduce more rapidly in warmer conditions.
- BThe region has seen a significant decrease in the population of the beetle's natural predators.
- COther invasive species in the region have not shown similar population increases.
- DThe biologist's research was funded by an organization advocating for climate change awareness.
Show answer & explanationAnswer & explanation
Correct answer: B. The region has seen a significant decrease in the population of the beetle's natural predators.
The biologist attributes the beetle population increase solely to warmer winters. Option B introduces an alternative cause—a decrease in natural predators—that could also directly explain the population increase, thereby weakening the biologist's conclusion that warmer winters are the *direct* cause.
Why the other options are wrong
- A. This would *strengthen* the biologist's argument by providing another mechanism by which warmer temperatures contribute to population increase.
- C. This might suggest the warming isn't universally impactful, but doesn't offer an alternative cause for *this* beetle's increase.
- D. This is an ad hominem attack on the biologist's motivation, which does not address the logical validity of the argument itself.
Alternative Cause (Causal Argument)
A flaw in reasoning where an argument fails to consider other plausible factors that could have caused an observed effect, attributing it solely to one specific cause.
- Weakens a causal claim by introducing competing explanations.
- Does not necessarily disprove the original cause, but reduces its certainty.
- Often seen when correlation is presented as causation.
Memory trick: Don't just point to one, there could be another one!