The effects of domestication and artificial selection on brain anatomy of the domestic chicken (Gallus gallus domesticus) and domestic pigeon (Columba livia)

Abstract

Domestication occurs due to captivity and artificially selecting animals for human benefit. One effect of domestication is a reduction in brain and brain region sizes of domesticated animals compared with their wild ancestors. However, little is known about the neuroanatomical effects of domestication on the world’s most common birds: chickens (Gallus gallus) pigeons (Columba livia). This study revealed that chickens and junglefowl share similar telencephalon composition, but they both differ significantly from wild galliform species. In addition, we show that homing pigeons have larger olfactory bulbs than show breeds, but not sporting or feral pigeons, suggesting that all free-flying pigeons might use olfactory based navigation. Taken together, these results revealed that captive breeding can exert complex effects telencephalon anatomy and how artificial selection can alter the size of sensory regions in the brain.