Evolvability is Evolvable

It has long been theorized that organisms that can rapidly change to suit their environment would be favored over those who cannot. But is the ability to evolve itself selected for, or does evolvability arise due to other evolutionary processes? Researchers at the University of Pennsylvania studying lyme disease-causing bacteria Borrelia burgdorferi have studied the genetic makeup of bacteria one year after infection in mice and compared this to the original sample. They found that natural selection favors those cells that have more genetic variation in an unexpressed series of DNA "cassettes". These cassettes recombine with the coding sequence for the bacterial antigen to produce new forms that can evade the host immune system. Since the cassettes are not expressed, their variability should not be selected for unless they actually contribute to "evolvability".

• The original paper