Posted by: Glow-worm PJ13 JUN 2012
It may seem surprising, given the huge diversity in size, shape and appearance of the domesticated dog (Canis familiaris), that it is only 15,000 years since mankind began domesticating wild wolves.
The diversity of type is due to the selective breeding of dogs to produce physical and behavioural characteristics that suited their human owners, and resulted in the more than 350 distinct breeds seen today. However, this interbreeding, combined with transport around the globe, means that the origins of domestication are still a mystery, and we are still no nearer
knowing which wolf populations were first used, or where in the world the first wolves were domesticated.
The genome of the domestic dog was first sequenced in 2005, and the first connection between a gene and an identifiable trait was discovered in 2007, when scientists linked the IGF1 gene with small body size in certain breeds. Until this discovery it was not known whether a characteristic such as small body size was controlled by one gene or by a whole set of genes.
Selective dog breeding has produced breeds with distinctive traits of behaviour, as well as appearance, and this has allowed researchers to target areas of the canine genome to locate genes governing appearance and behaviour by concentrating on those areas peculiar to the breeds in question. For example, in the search for a gene producing very short legs, they concentrated on areas of the genome peculiar to the dachshund.
Another study involved looking at narcolepsy in Doberman pinschers, and it is hoped that, by studying genetic influence upon behaviour in dogs on a molecular level, research may eventually lead to an insight into genetic influences on human psychological and behavioural problems, and possibly produce a treatment for these conditions.