The New World Screwworm Is Back. Hereβs What That Means.
Hereβs why farmers and scientists are concerned over the New World screwwormβs unwelcome return to the United States.

Β© Amir Hamja for The New York Times

Leishmania parasites appear to evolve through widespread genetic exchange, reshaping assumptions about how they adapt and spread. A parasite long thought to spread mostly by cloning itself may be far more genetically dynamic than scientists once believed. A new international study suggests that Leishmaniaβa group of microscopic parasites responsible for debilitating tropical diseasesβregularly swaps genetic [...]