Amphibian populations are declining

Answer choices

1. A

   Correct52% picked this

   Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type

   Why this is right

   Do we care if UV-B is the only type that damages genes? Would it weaken the argument if other types of radiation blocked by atmospheric ozone also damaged genes? Would that hurt the author's conclusion that the depleting ozone layer is the primary cause of what's killing amphibians? No, that would only strengthen it. Depletion of the ozone layer is scarier if the ozone usually blocks multiple types of gene-damaging radiation that if it only blocks one type of gene-damaging radiation. The more types of gene-damaging radiation that get through, the worse a depleted ozone layer is for amphibians, which just helps the author's conclusion. So, if anything, this answer weakens (not that it needs to in order to be correct).

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

   52%
2. B

   Boosts Plausibility3% picked this

   Amphibian populations are declining far more rapidly than are the populations of nonamphibian species whose tissues and eggs have

   This adds plausibility to the author's story by providing more data that declining population is tied to vulnerability to UV-B. The animals whose eggs are more vulnerable to UV-B are declining more, and since depletion of the ozone layer allows more UV-B to come through, it looks like depletion of the ozone layer could be hurting those animals.

   3%
3. C

   Boosts Plausibility2% picked this

   Atmospheric ozone has been significantly depleted above all the areas of the world in which

   This helps the plausibility of the hypothesis that "ozone depletion" is causing "amphibian population decline" by putting the Suspect at the Scene of the Crime. In order for ozone depletion to be the causal agent that's affecting amphibians, we need to put them in the same room together. If amphibians lived in areas of Earth where the ozone layer weren't depleted, then the author's hypothesis would be pretty far-fetched. A necessary assumption the author's hypothesis makes is that "at least some amphibians are getting more UV-B because of ozone depletion than they otherwise would", which assumes that amphibians live somewhere that there is ozone depletion. This answer gives us a strong version of that necessary assumption, saying, "Yes, everywhere that amphibians are declining, ozone depletion is present." (Cause and Effect appear together)

   2%
4. D

   Rules Out Alternate Explanation35% picked this

   The natural habitat of amphibians has not become smaller over the

   This strengthen by ruling out an alternate possibility for the primary cause of declining amphibian populations -- it's not because their habitat is disappearing.

   35%
5. E

   Boosts Plausibility7% picked this

   Amphibian populations have declined continuously for the last

   This strengthens the correlation between the putative cause and effect. We know that ozone has been depleting continuously for the last 50 years. If at the same time amphibian populations have been declining continuously, it establishes a strong correlation between what the author thinks is the Cause (ozone depletion) and what the author thinks is the Effect (declining amphibians). Anyone claiming that "X is causing Y" is corroborated by a correlation showing that "As X has increased, so too has Y increased".

   7%