Literrata: Kiger mustangs carry rare Iberian Sorraia mtDNA

A chalk drawing on a broken school desk I made for an art show.

Someone posted on Facebook a photo of dun-colored Kiger mustangs, a horse that carries a rare mtDNA recessive dun-color gene from Iberia, and I fell down the Google rabbithole. I noted the phenotype was similar to the endangered Iberian horses related to the Gallego, and Sorraia breeds. The Southeastern Oregon Kiger mustangs were originally flagged as being unusual because of their dun coloring. Instead of shooting the mustangs for dogfood, someone thought to sequence their mDNA. So, being a horse of a different color literally saved a rare genetic pool from extinction.

BLM photo of dun Kiger mustangs in southeastern Oregon

The BLM photos of the Kiger mustangs made me think of the autochthonous, or Neolithic CeltIberian Sorraia (closely related to the Marismeño) horse, also with rare mtDNA markers. Coat coloration was the clue. Horses that are dun colored (a bay, or chestnut dilution gene), or grey-dun grullo (an even rarer black dilution gene—neither roan, nor grey) not only carry a primitive recessive coloration gene, they often have dark faces and points with pangaré markings, body mottling, zebra-striped legs, and dorsal stripes—a primitive dun horse trait similar to those tarpan-like horses represented in paleolithic cave paintings. Their manes and tails are often bi-colored with white guard hairs and black upright manes like that of the feral Polish Konik horse, and the Heck. The wild Przewalski's horse has a solid black upright mane and tail.

Many equines appearing in prehistoric cave paintings such as in Chauvet cave are dun, and several closely related species in the genus Equus show dun characteristics. These include the Przewalski's horse...and an extinct subspecies of horse, the tarpan. —Wiki

Chauvet, Ardèche, France, 31 000 BP —Wiki

Contrary to popular belief, Spanish and Portuguese explorers didn't ship their prized Baroque Andalusian horses to the New World. Instead, they sent primitive native horses on long ocean voyages that lasted two months or more. Hardy and resistant, unlike the valuable blooded horses preferred by the nobility, those diminutive horses captured from the fens and marshes of Portugal, were practically breathatarians, and could survive the harshest of conditions, and subsist on little food or water.

Paleolithic artwork in Lascaux II, note the horse is pacing, not trotting—Wiki

Because the native ponies weren't valued as blood animals, they also nearly became extinct in both the New and Old Worlds via neglect and distain. The Sorraia was once hunted for food, and the Exmoor ponies of Britain was used for target practice during WWII, they were a source of illegal meat in the cities. During the 1970s, the BLM was infamous for slaughtering entire herds of mustangs for dogfood. And their nearest ancestor, the native American wild horse was probably also hunted to extinction during the Ice Age.

Cave painting of a dun horse at Lascaux; note the horse is pacing, not trotting —Wiki

(Note bene: A pony is not a miniature horse, or an immature horse, it is distinct from a horse in conformation and temperament. What generally distinguishes them apart is height: a horse stands at least 14.2 hands (4', 10") at the withers, while a pony clocks in under 14.2 hands. The average span of a hand is 4 inches. But those are just the obvious differences. Not only do ponies have thicker necks, raised manes and heavy tails to brave the elements, they have heavier bones, shorter legs, stronger pasterns, bigger hooves, and wider chests, smaller organs, and they have short heads. But don't let that apparent lack of headspace fool you. They're way smarter than horses too. My wily Shetlands were consummate escape artists.)

Icelandic horses were once called ponies but now they’re considered (small) horses, but that terminology is a moot point as they retain all the pony points mentioned above. I guess someone felt Icelandic ponies were being dissed in English, and the nomenclature had to undergo a definition change to be taken seriously. Ditto that with Connemara ponies. I mean “horses.”

(More on Connemara pony origins here.)

As it turns out, in Icelandic, there is no word to distinguish ponies from horses. To further confuse things, the term “pony” is also used to separate primitive equines from the modern breeds. But I also tend to use the word “pony” to distinguish the primitive breeds from modern horse breeds.

According to Etymology Online, the word Powny is attested in Scottish in the 1650s via Old French, via Latin pullus, meaning small. But during the Classical era, all horses were small. I suspect that the word pony arrived via the vocabulary of the Romano-Gaulish auxiliary cavalry— especially the Imperial Horse Guard or equites singulares augustii —as they worshipped Epona (the great mare), goddess of horses.

One Gaulish word for "horse" was epos (Old Breton eb and modern Breton keneb "pregnant mare") while Old Irish has ech, the modern Irish language and Scottish Gaelic each, and Manx egh, all derived from proto-Indo-European *h₁éḱwos. —Wiki

(The Irish, Manx and Scottish Goidelic speakers swapped Continental Celtic and British Brythonic plosive “P” sounds for more velar “Q/G/K” sounds. Consider it a lisp. So the Welsh word, Map, son, becomes Mac in Ireland—and the mutation flourished by colonial extension, Scotland, and the Isle of Man.)

But the beauty of these rare “pony” breeds (breed is a relatively new concept, the term phenotype is more accurate) is more than skin deep, their conformation is distinctive as well. Most are amblers, or two-beat pacers, another rare genetic predisposition—sort of like having four on the floor, plus overdrive in car terms. Think jennet, or palfrey in the Middle Ages, or modern Standardbreds, Walking horses, Icelandic horses/ponies, and Paso Finos—smooth rides, all at the walk or pace.

Here, we examine historic horse remains for the DMRT3 SNP, tracking the origin of gaitedness to Medieval England between 850 and 900 AD. The presence of the corresponding allele in Icelandic horses (9th–11th century) strongly suggests that ambling horses were brought from the British Isles to Iceland by Norse people.... Thus, early Icelandic horses already exhibited the ability for alternative gait as suggested by historic sagas [
2]. Although the origin of the Icelandic horse is not fully resolved, the general assumption is that horses arrived no earlier than around 1,100 years ago on the island together with Norse settlers from Scandinavia [
3,
4]. However, all Scandinavian horses in the dataset lacked the mutated allele, whereas it was present at a high frequency in early Icelandic horses. This high proportion cannot be explained by genetic drift alone. Given its presence in Britain in the early 9th century, it is improbable that the mutation appeared independently on Iceland and spread within the Icelandic horse population within such a short time. Rather, it is more likely that the first horses ever imported to Iceland already carried the ambling allele and that the Norse settlers preferentially selected for this trait which was then enhanced by the founder effect in this small island population... —The origin of ambling horses

Getting Brandy, the massive Standardbred chestnut gelding I used to ride, to break into a gallop, was nearly impossible. Ditto that with Helgar, an Icelandic pony I also rode, he was a house afire, but when he tólted, your chin needed a sportsbra to stay on.

Although ambling gaits are seen in some Mustangs, and other Colonial Spanish Horses, DMRT3 mutations [that are responsible for ambling] are rarely seen in feral or wild horses. —Wiki

Epona, 3rd c. AD, Freyming, France. Note the horse is tölting. —Wiki

So, Oregon's Kiger mustang (some Kigers are gaited), along with the gaited Seminole, or Florida Cracker, and the isolated Sulphur mustang of Utah, represent archaic horse lineages that links back to the marshes and isolated regions of Iberia. The Garrano, another Celtic pony from northern Portugal, is also a laterally gaited breed. The Galician mountain pony is closely related to both the Garrano, and the dun-colored Sorraia.

The Garrano horse is believed to be an ancient breed, with Northern Iberian Paleolithic cave paintings depicting horses with similar profiles. The similarities between the breed and the depicted animals lead to the conclusion that the breed's appearance has remained stable. There is genetic evidence that the horse originates in Celtic regions... —Wiki

The Gallego, like other small breeds of the northern part of the Iberian peninsula, descends from small dark-coloured horses introduced by Celtic immigrants in the sixth century BC. —Wiki

Paleolithic art in the region depict equines with a likeness to the Sorraia, with similar zebra-like markings. Analysis of mtDNA on Mustangs... show similar mtDNA patterns between some mustangs and Sorraias. Spanish conquistadors took Iberian horses... to the Americas, as pack animals. Similarities between the Sorraia and several North and South American breeds are shown in the dun and grullo coloring and other characteristics. The Sorraia, their ancestors, with similar features, may have had a long history in the Iberian region and a role in the creation of American breeds. —Wiki

At one point, during my travels to Latin America, it dawned on me that those skinny ragged village horses (especially the island, or mountain horses), like the one I rode in the Andes, who would rather pace or trot than break into a gallop—might also be related to the archaic Iberian horses. Treated little better than donkeys, they were not considered valuable, but were able to survive the harshest of conditions, and were largely ignored as unimportant beasts of burden. But they also carried traces of the ancestral gene pool related to the extinct New World horse. Now DNA sequencing is proof-positive that my hunches hold some validity.

Upper Paleolithic Ochre Horse head engraved on a rib fragment. was unearthed in 1876 the Robin Hood Cave at Creswell Crags, Derbyshire, Britain.

Then I found this genetic study:

Iberia was the source of much of the original stock that was used to populate the New World with horses.... The second haplogroup ... includes Marismeño horses (stripped horses from the Guadalquivir salt marshes) that, like the Sorraia, are considered a primitive Iberian equine type.... The high frequency of New World horses in this haplogroup may be explained by historical records... mares taken to the American continent by Christopher Columbus and during the subsequent Spanish colonization, were bought from the stock bred in the islands and salt marshes of the Guadalquivir River.

Of the three geographic regions studied, South America is the only one having sequences that belong to haplogroup C617C, and ... haplogroup C601C. Indeed, the only non–South American samples that belong to this latter haplogroup are two individuals from the Caballo de Corro breed, a Celtic origin pony from Asturias.... who consider this as distinctive for northern European ponies, known to have Celtic origin (that)... may indicate common matrilineal ancestors between Celtic ponies and South American breeds... in 1508 the Spanish crown authorized the transport of 40 Celtic type horses (small and resistant) in the expedition organized by Alonso Ojeda and Diego Nicuesa to Panama.

New World breeds have a high frequency of haplotypes of Iberian origin and represent a subset of the diversity found in Iberia. Therefore, this study supports the historically documented Iberian origins of New World horses.—Iberian Origins of New World Horse Breeds

I think the Caballo de Corro mentioned in the study above refers to is the Asturcón, another gaited Celtic pony. There is no specific reference on the Internet to caballo de corro.

The Asturcón has been documented since Roman times: it has an unusual ambling gait, described in the epigram of Martial, and by Pliny the Elder in his Naturalis Historia, where he describes its characteristic ambling gait. (The Latin word asturco was later used for other similar small horses with ambling gait.) It is of Celtic type, and shows similarity to the Pottok and Losino of Spain, the Garrano of Portugal, and the Dartmoor, Exmoor, Fell, Highland, Shetland and Welsh breeds of the British Isles.—Wiki

Added to the list of archaic ambling Iberian phenotypes in Canada’s Sable Island ponies were aboriginal Breton ponies. The native Breton horse was outbred to many non-native introduced breeds, including Arabians—especially during the 19th c.—it’s difficult to find any information on them, let alone, purebreds. But I found this:

“The Breton bidet seems to have been used by the Celtic warriors who occupied Armorica in ancient times: according to Commandant Saint-Gal de Pons (in the 8th c.), the Celts migrated with small horses with a primitive coat (buckskin or grullo with markings), which formed the stock of the Breton bidet”. —Wiki

Early sources mention that the Breton bidets ambled in the 5th to 8th cs., long before the introduction of hot-blooded (Arabian & Norman) horses into their gene pool in the 12th, and 19th cs. Their ambling gate also made them popular as palfreys during the Middle Ages. Their diminutive size kept them out of the military, both the Napoleonic War, and World War I. But they perished to the whims and vagaries of modern breed aesthetics.

If you really want to torture yourself, there's a great mitochondrial horse family tree, sort of an equid who's-who map in a PNAS paper, Mitochondrial DNA and the origins of the domestic horse. "Relatively recent bottlenecks are also reflected in the mitochondria, namely in the Senner, Sorraia...locally regarded as indigenous."

Epona and her horses, Köngen, Germany, ca. 200 AD.—Wiki

In the 1990s, as I was studying medieval Celtic literature, I realized that the sculptures of the Celtic Matronae were represented on small gaited horses, or ponies. The Celtic ponies paced (or tólted—where front and back legs don't move diagonally, but laterally), which is a recessive trait. The Gaulish horse goddess Epona ("the Great Mare", from whence we get the word, pony, or so I’m told), and Welsh Otherworld Celtic diety, Rhiannon, rode gaited ponies. Smooth rides. And the medieval descriptions of the ponies' coloring sounded like it was grullo, another rare, recessive trait that the marginalized wild horses of Portugal also carry.

Epona, 2nd-3rd C. AD, Contern, Luxembourg —Wiki

Exmoor ponies of southwest England also carry similar primitive, native genes. "Exmoors are believed to be the most primitive of the northern European horse breeds, and the breed’s antiquity and genetic distance from other breeds has been demonstrated." (Livestock Conservancy). There are accounts of Bronze Age Britons racing their ponies with two-wheeled chariots as early as 400 BC, and until recent times, Exmoors were used as pit ponies, there was significant mining on Exmoor during the Roman occupation. "Roman carvings, showing British and Roman chariots pulled by ponies phenotypically similar to the Exmoor, have been found in Somerset" (Wiki). A carving dating from the Roman era depicts a pony with a characteristic “toad” eye, an extra eyefold, and the Bayeux Tapestry of 1066, depicts a pony resembling an Exmoor, carrying a warrior. (The Horse Guide).

9th c. Bullian stone, Pictish horse is ambling, not walking —Wiki

Britain's oldest aboriginal pony, the Exmoor, is probably as close as one can get to the original wild horse native to North America. The mummified remains of late Pleistocene native Yukon ponies preserved in the Alaskan permafrost (Bereigia), shared the same unique jaw type as the Exmoors, and other genetic traits. (In 2013, scientists analyzed the oldest DNA ever recovered in the world, of a 700,000 year old Ice Age horse, found in a gold mine on Thistle Creek, in the Yukon.) Equus caballus originated ca. 1.7 million years ago in North America and traveled to Asia. The Yukon wild horse, E. lambei, died out between 13,000 and 11,000 years ago, at the same time that the Exmoor ponies roamed the forests and fens of the British Isles.

The Exmoors came so very close to extinction, like the Sorraia, and other native European horses. Because they weren't valued as bloodstock, all was nearly lost forever. (The idea of breed is a new term). Ironically, the hardy Exmoors contributed the foundation blood to several modern breeds including trotting horses and the Thoroughbred hunter.

But now, with mtDNA testing, the rare genetic sequences in several horse breeds have been isolated, and measures have been taken to preserve these ancient horse phenotypes including the gene pool of the Kiger mustang. Dr. Jay F. Kirkpatrick, in The Surprising History of America's Wild Horses, makes a compelling argument:

[T]he Mongolian wild horse (E. przewalskii, or E. caballus przewalskii) disappeared from its habitat in Mongolia and northern China a hundred years ago. It survived only in zoos and reserves....Then surplus animals were released during the 1990s and now repopulate a portion of their native range in Mongolia and China. Are they a reintroduced native species or not? And how does their claim to endemism differ from that of E. caballus in North America, except for the length and degree of captivity? —LiveScience

Though the wild horses of North America are considered non-native invasive species by federal and state agencies—they're not. They were merely reintroduced to their native homelands, after a 7,600 to 12,000-year absence, with a little help from the Spanish conquistadors. After all, humans might have been responsible for driving the North American horse to extinction, to begin with. The Kiger mustang is an integral part of that enduring legacy that is the story of the horse in the Americas.

A relief of Epona, flanked by two pairs of horses, Roman Macedonia.—Wiki

horses ability to pace is written in their DNA

original post: Iberian horses related to Gallego, or Luisitanos by the look of it. There is also the ancestral CeltIberian Sorraia (related to the Marismeño) horse with rare mtDNA markers, and are often dun or gruillo colored, with zebra-striped leg, and dorsal stripes—a primitive horse trait similar to those horses represented in cave paintings. Small and resistant, they traveled well—to both Iceland, and the New World, and unlike the more valuable horses, they could survive the harshest of conditions. Then it dawned on me that isolated horses of the New World (especially on islands) might also be related to the Iberian horses. (Florida Crackers are a related Iberian genetic isolate). I was studying medieval Celtic literature, and realized that the sculptures of the Matronae were represented on small gaited horses, or ponies.