Sniffing out dogs’ wolfish past
Dogs are our oldest animal companions and have probably lived alongside humans for at least 15,000 years. Over many centuries, careful breeding has produced dogs that vary hugely in shape and behaviour. All dogs are said to share the same wolf ancestors – but do they?
For a long time, scientists have wondered where and when humans and the wolves first learned to live together (a process called domestication). However, different approaches to the question have produced lots of answers. Now a new study suggests an explanation for the confusion – our modern canine pals may be descended from two different groups of wolves that learned to live with humans in separate events. An international team of scientists, led by Pontus Skoglund of London’s Francis Crick Institute, collected remains from 72 wolves found across Europe, Asia and North America. The wolves lived at various times over the past 100,000 years. The team studied their DNA (a complex chemical found in all living things, which tells their bodies how to develop – see panel). Differences in the wolves’ DNA could be used to work out how far back they shared an ancestor and help the team to work out a rough family tree (a diagram of relatives).
When the scientists compared DNA from ancient and modern dogs with the prehistoric wolves, they found the closest match was to wolves from eastern Asia – but some dog breeds from western Asia and Africa, such as the basenji, also had DNA that could only have come from European wolves. This suggests that either the ancestors of these particular dogs bred with local wolves after reaching Europe, or that wolves were domesticated twice, and their doggy descendants bred later when they met each other. However, none of the ancient wolf DNA was a perfect match for dogs, so the exact spot where wolves became dogs remains a mystery – for now.