Evolution Can Select for Evolvability, Penn Biologists Find

Evolution does not operate with a goal in mind; it does not have foresight. But organisms that have a greater capacity to evolve may fare better in rapidly changing environments. This raises the question: Does evolution favor characteristics that increase a species’ ability to evolve?

For several years, biologists have attempted to provide evidence that natural selection has acted on evolvability. A new paper by University of Pennsylvania researchers offers, for the first time, clear evidence that the answer is yes.

For species of viruses, pathogenic bacteria, and parasites to survive, they must be able to rapidly adapt and evolve, which lets them stay one step ahead of their hosts’ immune systems. The researchers evaluated 12 strains of the Lyme disease bacteria for signs that natural selection had acted to increase diversity.

“The evidence was remarkably strong in favor of evolution for more diversity, and thus greater evolvability in the expressed protein,” said Assistant Professor of Biology Dustin Brisson, the senior author on the study. 

Coauthors at Penn include biology post-docs Christopher J. Graves and Vera I. D. Ros and Professor of Biology Paul D. Sniegowski. The study was published in the journal PLOS Pathogens.

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