Researchers and scientists studied the history of horses and their genetics and found that its diversity declined after modern breeding started to happen.
An international team of 121 scientists published their study in the journal Cell on Thursday, showing that through compiling the genetic history of horses, they found out that modern breeding practices lessened the horse’s diversity in the past 200 to 300 years ago.
After dogs, cattle, and pigs, humans domesticated horses, too, around 5,500 years ago. People started to ride, milk, and lock horses in pens 5,500 years ago, and it has never been the same again for the animals.
“The horse had a profound effect on human history,” Ludovic Orland, a research director with CNRS and the University of Toulouse and coordinated the study, said. “We were able to go faster, further, and to conquer new territories. We went to war differently. We were able to plough fields and do agriculture.”
The team then though about the ancestors of the current domestic horse and analyzed the genomes of 278 specimens, which were mostly horses, donkeys, and mules across Europe and Asia.
Ancient genetics research saw a major technological leap in 2010, which drove another team of experts in a Toulouse laboratory to extract and analyze DNA from bones that were not available and accessible before.
Through that research, they discovered that an ancient line of horses were present in Iberia until at least 4,000 years ago, before they actually mysteriously disappeared completely. Meanwhile, another lineage of ancient horses in Siberia also disappeared around the third millennium BCE.
“They are a sort of horse equivalent of what Neanderthals are to modern humans,” Orlando said.
There are two lineages that remain today, which are the Przewalski’s horse and the Mongolian wild horse – both of which originated in Central Asia.
However, the scientists still haven’t found any genetic ancestor until now.
By the 16th and 17th centuries, “pure” breeds emerged. “All the current breeds, from the Shetland pony to the Thoroughbred, were made then,” Orlando added.
During the Arab-Muslim expansion between the 7th and 9th centuries, invaders brought with them an oriental horse, which descended from the Persian empire of the Sassanids.
“What we picture as a horse today and what we picture as a horse from a thousand years ago or two thousand years ago was likely actually very different,” Orlando said. “Horse domestication is central to human history, and in 2019, we still don’t understand where it started. That’s mind blowing.”