Dangerous Times: Guppies don’t follow rules for old age

A new study of wild guppies could unsettle a decades-old idea about the role of danger in the evolution of aging.

GUPPY SUPERGRANNY. Pictured shortly before her death, this guppy reached the age of 4 years and 64 days. D. Ghalambor

Biologists in the 1950s predicted that in a treacherous habitat, creatures would evolve so that they’d age rapidly, explains David N.