How domestication changed rabbits’ brains
Study sizes up differences in the ‘fear centers’ of wild and tame bunnies
RABBIT REMODELING Domestication of wild rabbits (left) physically changed the animals over time, including their brains. A domesticated rabbit is shown on the right.
FranciscoMarques/shutterstock (left); Grigorita Ko/shutterstock (right)
Domestic rabbits have smaller brains relative to their body size than wild rabbits do, a new study determined. And that’s not the only change getting tamed by humans wrought on bunny brains.
Two “fear centers” are the most altered brain regions between wild and domestic rabbits. Domestic rabbits have smaller amygdalae (emotion-processing centers that play a key role in the fight-or-flight response) and larger medial prefrontal cortices (thought to be involved in social behavior) than wild rabbits, an international group of researchers report online June 25 in the Proceedings of the National Academy of Sciences.
Changes to the brain regions may have produced animals less fearful of humans.
Bunny brains
Transparent images of rabbit brains illustrate that a wild rabbit, left, has larger amygdalae (yellow) and a smaller medial prefrontal cortex (blue) than a domestic rabbit, right. Those parts of the brain may have changed during domestication because they are involved in fear.
