Cells take on traveling salesman problem

Immune system actors map a perfect route in simple version of math dilemma

Forget GPS. With no fancy maps or even brains, immune system cells can solve a simple version of the traveling salesman problem, a computational conundrum that has vexed mathematicians for decades.

The new research, which simulates how a type of white blood cell seeks and destroys infectious particles, shows how living things — be they cells, sharks or bees — successfully find a target, with only limited information and even more limited cognitive skills.