TINY KILLERS Acquiring one gene and one mutation allowed these plague bacteria, Yersinia pestis (shown in yellow in a flea’s digestive system in this colored scanning electron micrograph), to cause deadly pandemics.
ACNE ACCELERATOR Vitamin B12 can lead normal skin bacteria called Propionibacterium acnes (shown in artist’s rendition) to pump out pimple-producing chemicals.
V. Altounian/Science Translational Medicine
ILLEGAL IVORY Poachers stand over the body of an elephant killed for its tusks. With a genetic analysis of seized ivory, researchers have pinpointed two major poaching hot spots in Africa.