Why Do Cats Purr?
The results of a new study has revealed the changes to the genome of felines that cause kitty cats to purr for treats and snuggle up to their human owners. Genetic changes have reduced the cat’s fear of new situations and altered their motivation to actively seek out rewards according to Dr. Wesley Warren, the co-author of the study. The relationship between humans and cats is an old one, with some studies suggesting the cat was first domesticated approximately 9,000 years ago in the Middle East. Other studies reckon the cat was first domesticated 5,000 years ago in China. Whichever theory you believe, what everyone can agree on is cats and humans go way back.
Domestication is quite rare
Whilst it might seem quite normal to have a relationship with your tabby, the fact of the matter is that in the animal world, domestication of animals is actually quite rare. There are only a handful of animals that have been domesticated such as the dog, cow, horse, chicken, sheep, goat and pig, and scientists were completely in the dark when it came to which genes are responsible for domestication.
Cats have genes linked to fear and motivation
Scientists sequenced the genome of an Abyssinian cat back in 2007 in an attempt to find out which genes were responsible for domestication. Unfortunately they did not manage to complete the analysis so they were not able to say very much about which genes underpin the process. Dr. Warren and his team did a secondary sequence of the same cat’s genome and also sequenced the genomes of a number of other domestic cats and a couple of species of wildcat. They then compared the results with the tiger genome, the dog genome and the genomes of a few other animals. What they found was that domestic cats have genes which are strongly linked to fear and motivation, both of which have evolved over time and resulted in cats becoming less fearful and more driven by rewards Dr. Warren said.
The difference between cats and dogs
In comparison to cats, dogs have lots more copies of genes for smell receptors which is probably the reason why they have such an amazing sense of smell. Felines (both big and small) have strongly selected genes for keen hearing and night vision which goes a long way to explaining why the species are such expert hunters Dr. Warren added. The study is still a inconclusive because it identifies only large gene regions that have been altered in the domestic cat and it is not obvious exactly how those genes are regulated or what those genes do. In order to be able to understand that, researchers will need to focus on very specific gene regions and study animals that have different versions of the genes and come to an understanding of their behavioural effects. So whilst we now have an idea of why the cat purrs, it is still only a general one.
