If it was not for the diminutive Shetland pony, horse racing might well have been a sport for plodders rather than kings, research has revealed.
An Irish scientist behind the discovery of the highly-prized speed gene in thoroughbreds has traced its origins back 300 years to mares from the much-loved British breed.
Genetic tests by University College Dublin's Dr Emmeline Hill found that the modern flat racehorse's make-up may have as much to do with quirky Shetlands as classy Arabian stallions.
"Changes in racing since the foundation of the thoroughbred have shaped the distribution of 'speed gene' types over time and in different racing regions," she said. "But we have been able to identify that the original speed gene variant entered the thoroughbred from a single founder, which was most likely a British mare about 300 years ago."
Dr Hill's study showed that the speed gene entered bloodlines when the Darley Arabian, the Godolphin Arabian and the Byerley Turk were bred with native British horses, mainly Shetlands, but also the now-extinct Galloway.
Based at the Equinome company in UCD she founded with Derby-winning trainer Jim Bolger, Dr Hill genetically tested almost 600 horses, 40 donkeys and two zebras to trace speed gene C-type myostatin.
The experiment also looked at pedigree lines and included 22 Eurasian and North American breeds, museum bone and tooth specimens from 12 legendary stallions born between 1764 and 1930, and 330 elite performing racehorses across three continents. "We wanted to understand where speed in the thoroughbred came from," Dr Hill said.
Undertaken along with co-author Dr Mim Bower from the University of Cambridge, the research, published in scientific journal Nature Communications, has traced all modern variants of the speed gene to the stallion Nearctic (1954-1973).
They also attribute wider expansion in bloodlines to Nearctic's son Northern Dancer (1961-1990), regarded as one of the most influential stallions of modern times.
Dr Hill, whose grandmother Charmian owned the legendary Dawn Run, the only horse to win the Champion Hurdle and the Gold Cup double at Cheltenham, was at pains to stress that there is no guarantee two sons or daughters will carry the same genetic make-up.