Natural selection favours those with a greater capacity to generate genetic variation.
Borrelia burgdorferi, the bacterium that causes Lyme disease, is skilled at
evading the immune responses of its animal hosts. STEM JEMS/SPL
Some gamblers succeed by spiriting cards up their sleeves, giving them a wider range of hands to play. So do some bacteria, whose great capacity for genetic variability helps them evolve and adapt to rapidly changing environments.
“There are other data that suggest that there could be selection on evolvability, but this is the first example where there really aren’t any other confounding answers for the data,” says lead author Dustin Brisson, an evolutionary biologist at the University of Pennsylvania in Philadelphia.