Researchers Solve The Mystery Of Horse Domestication
May 8, 2012

Researchers Solve The Mystery Of Horse Domestication

Brett Smith for

Just two days after the Triple Crown, scientists have determined that domestic horses, like the Kentucky Derby winner “I´ll Have Another,” originated on the grassy plains of modern-day Ukraine, southwest Russia and western Kazakhstan.

UK scientists at the University of Cambridge used a genetic database of more than 300 Eurasian horses to trace the origins of domestic breeds, according to their study published in the May 7 edition of the science journal PNAS.

Using this genetic information, several computer-generated models were created in an effort to understand possible domestication scenarios. Researchers determined that the domestic horse´s common ancestor, Equus ferus, inhabited the western Eurasian steppes around 160,000 years ago. They also said E. ferus descendants interbred with wild horses.

"Our research clearly shows that the original founder population of domestic horses was established in the western Eurasian Steppe, an area where the earliest archaeological evidence for domesticated horses has been found,” said Vera Warmuth, from the University of Cambridge's Department of Zoology.

“The spread of horse domestication differed from that of many other domestic animal species, in that spreading herds were augmented with local wild horses on an unprecedented scale. If these restocking events involved mainly wild mares, we can explain the large number of female lineages in the domestic horse gene pool without having to invoke multiple domestication origins."

This new theory explains some conflicting evidence found amongst different horse breeds´ mitochondrial DNA. A report published earlier this year in PNAS found that a wide range of E. ferus lineages underwent different periods of domestication across the Eurasian steppes. The report, authored by a team of scientists from around the world, also found E. ferus to be a common ancestor between domestic horses and the wild Przewalski's Horse.

Domestic breeds can be separated in to three different categories: hot bloods, cold bloods, and warmbloods. Hot bloods include Thoroughbreds, Appaloosas, Arabians, and Quarter Horses. These horses were bred for agility and speed. Many of these breeds are used for racing and some were historically used for light cavalry purposes.

Cold bloods are typically referred to as “work horses” and include Clydesdales and some ponies. These horses were bred for their strength and cool temperament, characteristics made that well-suited for pulling carriages and plows.

Warmbloods, like the Trakehner or Hanoverian, were bred as riding horses with more refined and milder temperaments. They were often the horses of authority or aristocrats as they were too small for heavy work, but too stocky for rapid travel. Today, many warmbloods are used as equestrian horses.

Przewalski's Horse is an endangered subspecies of horse found on the steppes of central Asia. The horse was extinct in the wild for a period of time, but was reintroduced recently through efforts made by the Przewalski's Horse Reintroduction Project of China. In 1992, the program released 16 horses into the wild and followed up this release with several other animals later on.  In 2011, Przewalski's Horse was reclassified on the IUCN Red List from “critically endangered” to “endangered.”