SFI External Professor Andreas Wagner considers RNA genotypes and their secondary structure phenotypes to resolve the paradox between robustness and evolvability. He writes that, while genotype robustness and evolvability share an antagonistic relationship, the phenotype robustness promotes structure evolvability. See Andreas Wagner, "Robustness and Evolvability: A Paradox Resolved," Proceedings of the Royal Society B - Biological Sciences 275, no. 1630 (2008): 91-100.