A killer has been caught in the act: the first before-and-after view of an infectious disease that led to an amphibian die-off has been released by the scientists who tracked it.

The results are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).

Like a wave, incidence of the fungal disease that wipes out Central American frogs--chytridiomycosis--advances through the region's highlands at a rate of about 30 kilometers ...