Two stationary kinds of bacteria can move when mixed

Speed increases as pair evolves together, study finds

Pseudomonas fluorescens

ISO A PAL  A Pseudomonas fluorescens bacterium (shown) and its colony get stranded when alone on dry surfaces, but mix in a different stationary species and evolution gets them moving.

 

Dr. Tony Brain/Science Source

WASHINGTON — Strand a fish on a tree stump, and neither swims away.