Trade-offs in the sizes of visual and olfactory organs are a common feature of animal evolution, but the underlying genetic and developmental mechanisms have not been clear. A study reveals that a single DNA variant that affects the timing of sensory organ development in fruit flies could explain the size trade-off between eyes and antennae, potentially providing a quick route to behavioral changes and adaptation.

Source: A single gene determines whether a fly has a good sense of sight or a good sense of smell