(Source: amren.com)
One Mutation Made It Easier to Ride Horses
Back in 2012, researchers from Sweden tied the amble to a very specific region of the genome, a single nucleotide to be exact. They found that a mutation of the DMRT3 gene altered the way that a horse trots, shifting its gait from the diagonal-pair trot to the same-side amble.
…researchers analyzed DNA from 90 ancient horses dating to over 5,000 years ago, and found the first instance of the mutation occurred in two horses from the York Archaeological Collection, dated to between 850 and 900 A.D.The horses originated in medieval England, they say, and were likely taken to Iceland by the Vikings, where they were interbred to produce a population of the gaited variety. From there, these superior comfortable horses spread across Europe, resulting in the wide distribution and diversity of gaits evident today.