Male-type aggressive and courtship behaviors of the fruit flies are differentially specified by two sex-determining genes, providing a substrate for the evolution to sculpt these two behaviors independently.
A domain-general structure learning mechanism, supported by anterior insula, moves beyond explicit category labels and dyadic similarity as the sole inputs to social group representations and predicts ally-choice behavior.
Phylogenetic analyses demonstrate an evolutionary trade-off between the amount of harm inflicted by a broad host-range virus and how effectively the virus positions itself within plants to enable onward transmission.
Hybridization and introgression blur species boundaries and broaden genetic diversity available for adaptation; and widespread introgression underpins the evolution of races of the generalist pathogen Albugo candida that specialise on different host plant species.
Parallel horizontal gene transfer has spread a bacteriolytic gene family to all domains of life, and has bestowed a niche-transcending adaptation in recipients that must deploy antibacterial molecules to survive in a bacterial world.
Evolutionary novelty is promoted by a macroevolutionary pulse of developmental plasticity, but is enhanced by secondary fixation, which permits developmental character release and further morphological exploration.