Cryptic genetic variation helps populations adapt to new environments

Cryptic genetic variation is standing genetic variation¹ that does not normally affect organismal traits, but that can upon perturbation, such as an environmental change. This is shown in an experimental study by Jia Zhang, and Andreas Wagner of the Institute for Evolutionary Biology and Environmental Studies at the University of Zurich, and Joshua L. Payne, Assistant Professor of Computational Biology of the Institute of Integrative Biology (IBZ) at ETH Zurich. Previous studies have already shown that cryptic genetic variation can facilitate adaptation to new environments, but the underlying molecular mechanisms remained unclear.

The experimental study used evolving populations of fluorescent proteins to show that cryptic genetic variation facilitates adaptation to new environments by providing access to adaptive mutational paths that would be otherwise inaccessible. It does so because it often includes mutations that would be individually detrimental to the organism in the new environment, but that serve as stepping-stones to combinations of mutations that are advantageous in the new environment. The accumulation of such mutations prior to an environmental change therefore renders an evolving population well poised to adapt to new environments.