Experiments on Drosophila show that an evolutionarily conserved photoreceptor that senses light outside of the retina can regulate responses to direct visual cues.
The presence of an organelle called the fusome in species as diverse as Drosophila and mammals indicates an ancient, conserved programme of germ cell development.
Experiments mapping individual neurons in the sensorimotor cortex of mice show that sharp transitions in functional properties can define cortical regions.