New Research on Epistatic Interactions Shows "Overwhelmingly Negative" Fitness Costs and Limits to Evolution

Two new papers published in the journal Science are reporting the results of studies on genetic interactions of mutations--a phenomenon called epistasis. While epistasis is sometimes cited as a potential mechanism for improving evolutionary fitness or overcoming fitness costs, these studies found the opposite. According to the research, as mutations--even beneficial mutations--accumulated, negative interactions among the mutations caused fitness to decrease. A ScienceDaily news...