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 sexually dimorphic circuit node controls a persistent, internal state that promotes fighting and mating in Drosophila, revealing parallels with mammalian systems suggestive of a conserved circuit "motif" controlling social behaviors.
The cellular behaviours that underlie the internalization of the multilayered endoderm anlage in Xenopus laevis link the ancestral mode of vertebrate gastrulation to common, epithelial-based mechanisms of gastrulation in non-vertebrate animals.
Both within and between hosts, the key factor guiding whether increasing treatment strength will increase or decrease antibiotic resistance is whether inter-strain competition is effective, not whether it is present.
Functional recapitulation of a likely evolutionary gain in gene expression shows that two genes are sufficient to switch mesoderm cell internalization from stochastic cell ingression to coordinated epithelial invagination.