Our work includes several unexpected discoveries that go far beyond state of the art. One of them resolves a decades-old question in evolutionary genetics: Is cryptic variation important for successful Darwinian evolution, and if so, why? The answer is yes, because cryptic variation can reveal unexpected new phenotypes in a new selective environment.
Another breakthrough discovery resolves a long-standing controversy about the question whether evolvability can itself be subject to Darwinian evolution. It proves that the evolvability of a protein can evolve adaptively through DNA mutations that increase its ability to fold, and thus its robustness to thermal noise. In doing so it not only proves that evolvability can evolve, but that it can increase very rapidly through Darwinian evolution.
A further substantial discovery is that Darwinian protein evolution can be accelerated by low temperature, whereas almost all biological processes are accelerated by high temperature. The work is especially important because, first, it is the first experimental study to assess the effect of temperature on phenotypic evolution. Second, it also explains why low temperature accelerates evolution. Mutations that bring forth a new phenotype destabilize evolving proteins, but do so much less strongly at low temperature, because low temperature renders proteins more robust to mutations and to thermal noise, a core subject of the project. Third, the discovery has potentially large practical implications. For example, it shows that low temperature can help protein engineers evolve proteins with new functions, because it helps function-altering mutations to manifest their beneficial effects. It also has implications for how we mitigate the temperature increases caused by global climate change, because high temperature may impede evolutionary rescue – the ability of populations to adapt to otherwise lethal temperature increases.
