BACKGROUND Antibiotics are among the most important tools in medicine, but their efficacy
is threatened by the evolution of resistance. Since the earliest days of antibiotics, resistance …

Evolvability is the ability of a biological system to produce phenotypic variation that is both
heritable and adaptive. It has long been the subject of anecdotal observations and …

Evolution is the hallmark of life. Descriptions of the evolution of microorganisms have
provided a wealth of information, but knowledge regarding “what happened” has precluded …

The same mutation can have different effects in different individuals. One important reason
for this is that the outcome of a mutation can depend on the genetic context in which it …

How complex are the rules by which a protein's sequence determines its function? High-
order epistatic interactions among residues are thought to be pervasive, suggesting an …

In experimental evolution, laboratory-controlled conditions select for the adaptation of
species, which can be monitored in real time. Despite the current popularity of such …

The structure of fitness landscapes is critical for understanding adaptive protein evolution.
Previous empirical studies on fitness landscapes were confined to either the neighborhood …

There has been much debate about the extent to which mutational epistasis, that is, the
dependence of the outcome of a mutation on the genetic background, constrains …

Antibiotic resistance represents a growing health crisis that necessitates the immediate
discovery of novel treatment strategies. One such strategy is the identification of collateral …

Bacteria evolve resistance to antibiotics by a multitude of mechanisms. A central, yet
unsolved question is how resistance evolution affects cell growth at different drug levels …