Adaptational tradeoffs constrain the evolutionary pathways towards antimicrobial resistance, but highly fit mutants are nevertheless likely to arise at any concentration of the drug.

The extra dimensions in protein sequence space open up indirect paths of adaptation and alleviate the constraint on the selective accessibility to high fitness genotypes.

Chemical perturbation-dependent deep mutational scanning data collected by a lab-based interdisciplinary graduate class resolves a paradox between the high evolution conservation and the high mutational tolerance of the protein ubiquitin.

A new mathematical approach can infer higher order genetic interactions from pairwise fitness comparisons between genotypes.

Whole genome deep sequencing of many longitudinally sampled HIV-1 populations reveals that reversions towards ancestral HIV-1 genome sequences occur throughout the course of infection.

Rectangular order perturbations generalize sign epistasis, capture global aspects of fitness landscapes, and clarify how rank order approaches relate.

Predictable patterns of fitness evolution observed in microbial evolution experiments can emerge generically as a consequence of widespread epistatic interactions between mutations.

When an essential metabolic gene in E. coli is mutationally inactivated, subsequent evolution rarely reverts the mutation to wild type but rather follows unexpected paths that rewire metabolic fluxes.

The wtf meiotic drivers change the fitness landscape of meiosis in outcrossed Schizosaccharomyces pombe demonstrating that genetic parasites can favor the evolution of variants that disrupt meiotic fidelity.

A description of evolution that is based on birth-death processes, and in which fitness is at most a derived quantity, is advocated.