Population output variability in a motor control system varies across levels (CPG, motor neurons, muscles) and can be ascribed to life history differences among animals and in some cases to differences between bilaterally homologous elements.

Human infants can use various muscle activations as soon as birth to produce rhythmic leg movements, but the strategy underlying this variable output seems to change between the first months of life and toddlerhood.

Arabidopsis shows extensive genetic diversity in germination time distributions, which can be explained by the underlying ABA/GA network functioning as a noisy bistable switch.

Similar evolutionary pressures on gene expression between human and chimpanzee populations contribute to the observation that inter-individual gene expression variability is similar across genes in these species.

Sex differences in trait variability imply that both sexes should be included in biomedical trials, using sex-specific statistical power calculations.

The nearly universal nature of scaled cell shape variability in an epithelial monolayer is unavoidable, irrespective of health or disease, as it comes from a mathematical property.

Time-varying states of alertness that shape behavioral responses may be detected from fMRI signal patterns.

Whether central vestibular neurons implement faithful stimulus encoding for the vestibulo-occular reflex or optimized coding via temporal whitening for other vestibular functions is determined by neural variability.

A flexible transcription initiation architecture and a uniform regulatory grammar buffer expression variability and the effects of genetic variants on essential genes while a rigid transcription initiation architecture and a diverse regulatory grammar ensure condition-specific responsiveness of other genes.

By demonstrating song learning-related synaptic strengthening and pruning in the vocal control circuits of songbirds, and showing how such changes can reduce the sensitivity of the circuit to ‘noisy’ inputs, a simple neural circuit mechanism for regulating motor variability during motor skill learning is identified.