|The speedy, almost comical horse step known as an ambling gait originated in England in the middle of the Ninth Century, scientists say.|
The gait, which makes horses comfortable to ride on long journeys, is an inherited trait that springs from a single genetic mutation.
According to this new analysis, it first appeared in horses in York about AD850.
Vikings took these horses to Iceland, and the trait spread globally.
Horses have three essential speeds:
However, a four-beat rhythm, where the horse moves both legs on the same side at the same time has long been a prized feature of some breeds.
Called an ambling gait, the step produces a much smoother ride, particularly over longer distances or rough terrain. It is as comfortable as a walk but the horse goes as fast as a trot.
In 2012, researchers examined Icelandic horses, and discovered that a single mutation in a gene involved in the movement of limbs was responsible for this ambling ability.
In this new study, scientists extended their search for the origins of this variation of the DMRT3 gene by examining genetic material from 90 horses, some dating back before 3500BC.
The earliest examples they found were in samples from York dating between AD850 and AD900, when the area was being raided and temporarily settled by Vikings.
"The first occurrence of this mutation was in two samples from medieval England from the York Archaeological Collection," said one of the authors, Dr Arne Ludwig, from the Leibniz Institute for Zoo and Wildlife Research.