Drivers of avian genomic change revealed by evolutionary rate decomposition.

Modern birds have diversified into a striking array of forms, behaviours and ecological roles. Analyses of molecular evolutionary rates can reveal the links between genomic and phenotypic change, but disentangling the drivers of rate variation at the whole-genome scale has been difficult. Using comprehensive estimates of traits and evolutionary rates across a family-level phylogeny of birds, we find that genome-wide mutation rates across lineages are predominantly explained by clutch size and generation length, whereas rate variation across genes is driven by the content of guanine and cytosine.

Pervasive relaxed selection in termite genomes.

Genetic changes that enabled the evolution of eusociality have long captivated biologists. More recently, attention has focussed on the consequences of eusociality on genome evolution. Studies have reported higher molecular evolutionary rates in eusocial hymenopteran insects compared with their solitary relatives.