Selective breeding has produced major changes in how our dogs look like. But recently, researchers have uncovered some major changes in the dogs' brains have taken place due to artificial selection through breeding. These changes are about the position of the brain and the region with smell control is located.
In dog breeds with short snouts the brain has rotated forward with as much as 15 degrees. The region in the brain that controls smell was relocated, according to researchers from the University of New South Wales and University of Sydney. They have used magnetic resonance imaging to analyze brains of dogs for a number of breeds.
The size and shape of the skull appeared to be correlated with brain rotation and positioning of the olfactory lobe. When the dog's head and skull shape become flatter, the brain rotates forward while the smell center goes further down towards the lowest position in the skull. Human intervention in the dog biology through breeding is not comparable to the effects on any other animal. Researchers are going to study further how the changes in brain organization are linked to differences in dogs' brain function.
Artificial selection has led to breeds that work better when in visual contact with humans, sheep dogs and gun dogs being the most obvious examples. These breeds are better able to understand a pointing gesture. Researchers at the Eotvos University in Hungary have examined the performance of different breeds in making sense of pointing gestures of humans. The study was meant to shed light on the evolution of human communicative skills as well.
Dogs have been selected to live in a human environment and have engaged in interactions with humans for more than ten thousand years. Hungarian researchers have found that gun dogs and sheep dogs can follow a pointing finger but not hunting dogs, dogs used for underground hunting or livestock guard dogs and sled dogs.
Breeds that have short noses and eyes centrally placed are better at interpreting gestures compared to breeds that have long noses and eyes that are spaced widely. This is probably because of the retinal location that offers the best visual acuity.
Researchers at the University of Vienna, Austria had shown that dogs can classify complex color photos and separate them into categories much like humans. They had also demonstrated that dogs can learn by using a computer automated touch screen. This method proved that it could be useful for testing learning strategies and comparing cognitive abilities of different breeds.
While some researchers are studying how humans have collaborated with dogs and the genetic bases of this interaction, other researchers have thrown light on the connection between aggression in dogs and DNA that involved in neurotransmission in the brain.
Many healthy dogs are euthanized because they have behavioral problems, particularly if they are being aggressive towards people. Studying connections between genes and aggressive behavior in dogs might help us better understand the interplay between genetics and environmental factors that influence dogs' behavior.