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

Natural selection shaped CHC22 clathrin genetic variation in humans with different diets and potentially influenced the human insulin response.

Pathogens, particularly viruses, target the same genes over deep evolutionary time, resulting in shared signatures of positive selection and transcriptional responses at the same genes.

Complete mapping of human-adaptive mutations to the avian influenza PB2 protein shows how selection at key molecular interfaces combines with evolutionary accessibility to shape viral host adaptation.

An integrated biochemical and evolutionary analysis shows how enzyme specificity evolves after gene loss during genome decay, implicating relaxation of purifying selection as a driving force for functional divergence.

Plasmodium falciparum kelch13 mutations that cause artemisinin resistant malaria in Southeast Asia show markedly different patterns of evolutionary selection in Africa.

Environmental heterogeneity can dramatically reduce the efficacy of selection and alter the neutral evolutionary dynamics in microbial range expansions.