[Campbell Biology P.719] Based on Figure 31.27 and the accompanying text, what can be conclu... | Practice Question

Based on Figure 31.27 and the accompanying text, what can be concluded about the relationship between the chytrid fungus and the decline in yellow-legged frog populations in the Sixty Lake Basin?

  • A: The data clearly show a direct causal link, as all un-treated lakes experienced frog extinction.
  • B: The data indicate a strong correlation between the chytrid's spread and the drastic decline in frog numbers, especially in lakes not treated with fungicide.
  • C: The decline in frog numbers started well before the chytrid's arrival, suggesting other primary causes.
  • D: Treating lakes with fungicide had no significant impact on the frog populations.

Explanation

Figure 31.27 shows the spread of chytrid Batrachochytrium dendrobatidis through the Sixty Lake Basin from 2004 to 2008. The accompanying text states that frog numbers plummeted after the chytrid's arrival and that by 2009, only 38 frogs remained, all in lakes treated with fungicide. This strongly indicates a correlation between the chytrid's presence/spread and the decline in frog populations, with fungicide treatment demonstrating a positive effect on survival.