It's well known that breeding of dogs can affect fur color, body size and other qualities more associated with outward appearance, but a new study in the journal PLoS ONE has found that we are also changing the size and structure of dog brains.
(Images: PLoS ONE)
Lead author Taryn Roberts and her colleagues determined "that the remarkable diversity in domesticated dogs' body shape and size appears to also have led to human-induced adaptations in the organization of the canine brain."
Roberts, a researcher in the Faculty of Veterinary Science at the University of Sydney, along with Paul McGreevy and Michael Valenzuela took magnetic resonance image slices of canine brains. They chose dogs with a variety of different skull shapes, but paid special attention to what are known as brachycephalic dogs. These are dogs with particularly short, broad heads, such as some mastiffs. (Humans can be brachycelphalic too. The condition is also known as "flat head syndrome.")
The scientists determined that skull length, width and the position of certain parts of the dog brain, such as the olfactory lobe (tied to a canine's ability to smell), were all likely affected by our breeding of dogs.
"Furthermore, these findings were independent of estimated brain size or body weight," the researchers added.
They're not yet certain if the brain alterations have led to changes in behavior, but that could be possible. It could be the case that "dogs with different skull shapes may behave differently…
Further investigation of the inter-relationships between skull shape,
brain organization and behavior represent fascinating directions for
future canine research," the scientists conclude.