Developing T cells whose TCRs have relatively low reactivity experience very brief TCR signaling events, experience delayed positive selection, and retaina preselection gene expression signature as they mature.

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.

In contrast with earlier conclusions, negative selection has a major role in cancer evolution.

Deficiency of capicua, a transcription factor that suppresses autoimmunity, impairs positive and negative selection processes by attenuating TCR signaling in CD4⁺CD8⁺ double-positive thymocytes.

Differences in the usage of DNA repair pathways may give rise to the unique patterns of Y-linked mutations that, together with natural selection, shape rapid Y chromosome evolution.

Computational analyses, for the first time in plants, reveal how male-biased genes evolve faster than female-biased and unbiased genes.

The T cell repertoire can display immunodominance to an epitope as a result of optimal positive selection in the thymus by one self-peptide/MHC ligand.

Background selection is shown to be the dominant mode of linked selection in humans, with marked effects on diversity levels throughout autosomes.

Analyses of spindle genes with missense changes in modern humans reveal evidence for positive selection since the split with archaic humans and show that modern humans interacted with Neandertals more than once in the past 200,000 years.

Comprehensive genomic and population genetic analyses of a non-recombining chromosome in white-throated sparrows reveal the actions of purifying selection, positive selection, and balancing selection, expanding our understanding of supergene evolution.