Domesticated rabbits are less afraid of humans than wild ones, thanks to few subtle genetic changes.

A new study by researchers at the Uppsala University shows that domestication of rabbits led to the genetic alteration in the rabbit genome. These changes were instrumental in reducing fear of humans in tamed rabbits.

What's really interesting in the current study is that it deals with the genetic structure of an animal that was tamed recently, about 1,400 years ago at monasteries in southern France. The region where rabbits were first domestic still has several wild bunnies, which act as excellent models for genetic studies.

For the research, scientists compared genome of wild rabbits Oryctolagus cuniculus with that of pet ones. The animals were from France and Spain.

The team said that the rabbit genomes had no major changes, however, there were subtle changes that were found in domestic breeds of rabbits, New Scientist reported. At least 100 of these gene variants were documented by the researchers.

The researchers say that wild rabbits did not lose any genes during domestication, rather the animals changed the activity of the existing genes, making some more active while dampening the expression of some others. For example, wild rabbits are known for their timidity; however, pet rabbits are less fearful of their human masters. This tolerance for human companionship was probably the result of a subtle shift in activity, rather than a drastic loss of a gene.

"Wild and domestic rabbits do not differ so much in actual protein sequences, but in how gene and protein expression is regulated," said  Leif Andersson at Uppsala University in Sweden, New Scientist reported.

"No previous study on animal domestication has involved such a careful examination of genetic variation in the wild ancestral species. This allowed us to pinpoint the genetic changes that have occurred during rabbit domestication," Andersson said in a statement.

The study is published in the journal Science.